It was summer and they were studying up in Castiel's room, sitting on his bed and no one was home. Dean thought when Castiel had asked if he wanted to come over to the empty house to study it didn't actually mean they were going to be studying. But here they were, sitting legs crossed on the bed, not even touch and Castiel was rattling off chemistry questions.

"What name is given to the natural catalysts found in living systems?" Castiel looked down at his notepad and then glanced up at Dean.

"Fuck if I know but I'm sure it's a beautiful name," Dean smiled and cast his eyes down to avoid the glare he knew Castiel was giving him now.

"Enzymes. The answer would be enzymes." Castiel looked back to his notepad to pick out another question. "What is the name of the bond that results in the formation of proteins?"

"You know I'm not into bondage Cas," Dean wiggled his eyebrows and started to lean forward but Castiel held up his hand as he looked back down to retrieve the answer.

"Peptide bonds and will you please try I know you know these answers. Or at least give me one related to chemistry?" Castiel was tapping his pen on the notepad and glaring again and this time Dean didn't look away.

"It's the summer, halfway over already, I don't want to be studying during the summer. You know when you invited me over to 'study'," he made the quotes with his hands to make sure Castiel knew his meaning, "in an empty house I didn't think you were serious." Dean brought his arms to cross over his chest.

"I am quite aware that summer vacation is nearly finished. I spent the first half alone thanks to you and I will not spend the second half alone as well. You brought this upon yourself." Castiel said pointedly.

"How is this my fa—?"

"If you hadn't screwed around during school you wouldn't have had to retake chemistry all of June and I swear to," Castiel stopped himself and Dean noticed he was actually getting a little mad here, "If you don't pass the final next Tuesday I know for sure your father will never let you leave the house until school starts. You're passing this damn test because I would actually like to see my boyfriend so shut up and answer the questions." Dean didn't speak but he nodded his head as if to say "Okay".

"What fraction of the elements on the periodic table are metals?"

"Uh, half?" Dean tried to make it seem like he was putting forth the effort now but he really didn't know the answer.

"It's three-fourths but you were close." Castiel smiled at Dean to reassure him he wasn't really mad anymore, "What element is common to many explosives?"

"Oh hey I actually know this one, Nitrogen!" Dean pumped his fist in the air and was still celebrating when Castiel leaned over the space between them and kissed Dean on the lips, hand reaching up to grab at his neck. He knew Dean would get this one right because he remembered how excited Dean was in early June when they learned about this and the teacher was thinking about doing a demonstration.

"What was that for?" Dean asked when he finally pulled away and Castiel scooted back to the other side of the bed.

"Think of it as incentive. Every time you answer correctly you get rewarded," Castiel looked straight at Dean's lips, "with a kiss."

Dean beamed, "I like this idea. Give me another one."

They went at studying like this, Castiel kissing Dean whenever he answered correctly, for about an hour and by the time there were only two more chapters to go over, they both looked like a mess. Castiel's lips were swollen from the kisses and the collar of his white button down was wrinkled from when Dean grabbed him, pulling Castiel to him, when Castiel smiled, saying Dean got the right answer. And Dean had shifted closer, closing the space that was in between them and he was sitting with one of the pillows thrown into his lap because he was seriously turned on by the way Castiel would look at him before asking a question he knew Dean would get right, meaning he knew he was going to get to kiss him again.

"Name one function of a protein?"

"Well there's structure, like hair and it can transport hemoglobin," Dean started staring off to the side as if he was reading the textbook in his mind, "then uh proteins regulate your metabolism like with insulin." Castiel beamed at him and leaned over to give Dean his reward but when Castiel broke from the single kiss Dean grabbed at his shirt collar.

"Nu-uh I gave you examples and shit, I get more than one kiss."

"But I only asked for one so you should only get one reward," Castiel said as he tried to pull away.

"Don't care," and Dean yanked Castiel forward to kiss again so more.

Castiel's balance was off and when Dean had yanked him he kind of fell forward, almost missing Dean's lips but he put one of his hands on the pillow in Dean's lap and pushed up to catch Dean's lips. When he did that Dean moaned and Castiel was suddenly aware of where his hand was placed.

"I'm sorry Dean. Did I hurt you?" Castiel pulled away and looked down, thinking he had accidently punched Dean in the crotch.

"No Cas, I'm fine just—"

"Oh," was all Castiel said when he realized Dean was trying to cover up his hard on. "I didn't realize. Maybe the whole kissing reward thing was a bad idea." Castiel nibbled on his lip because they had kissed a lot, a lot, but had never really gone further than that, Castiel always seemed to freak out, but now Dean was turned on and Castiel didn't know what to do.

"No, I liked the rewards deal," he glanced down and chuckled, "maybe a little too much but I feel like I'm actually learning the stuff now so can we continue?"

"Okay."

Dean got the next few wrong and Castiel wasn't sure whether it was on purpose so he could have time to cool off or if he genuinely did not know the answers. But the next one Castiel made sure was very easy so if Dean answered incorrectly Castiel would know it he was doing it on purpose. Dean hesitated as if he was contemplating giving the wrong answer before he sighed and answered correctly. When they kissed it was quick and Dean leaned back, repositioning the pillow on his lap again. But now Castiel was determined to make it up to Dean, make this fun again.

"What is the relationship between the temperature and pressure of a gas?" giving Dean a look that said If you don't give the correct answer when I know you know it, you're going to be in trouble.

"Direct and pressure increase together."

"Mmm yup," Castiel hummed before he leaned over to kiss Dean again, this time nipping at Dean's bottom lip, Dean's favourite thing, before pulling away with a smile on his face.

"What polymer is produced in the largest quantities?" That one caused Dean to smile because Castiel had already asked this question and Dean got it right the first time.

"Obviously polyethylene." Dean smirked.

"Obviously." Castiel repeated and when he leaned over to Dean he trailed his hand lightly up his arm, giving Dean goose bumps, before resting his hand on the scar Dean had on this shoulder. Castiel had caused Dean to get burned, not on purpose and Dean had forgiven him for it but Castiel always liked to pay special attention to it. Castiel took Dean's bottom lip in his teeth again, tugging a little before releasing and instead of pulling back Dean slipped his tongue into Castiel's mouth. Castiel gave a surprised noise but slowly broke away from Dean.

"We should get back to the questions."

"Right," was all Dean said as his eyes remained focused on the way Castiel moved his mouth.

"What is the main chemical component of sand?"

"Silicon oxide." Dean blurted out, already inching forward a little. Castiel leaned but kept just out of Dean's reach.

"So close," he whispered, breath hot on Dean's lips, "But the answer is silicon dioxide." Castiel began to move away but Dean grabbed him again.

"Screw this," was all Dean said before he pulled Castiel on top of him and then flipped them, pressing his weight into Castiel as he worked swirls in Castiel's mouth with his tongue.

Dean reached his hand down and hooked his finger into the top of Castiel's pants and that was fine, until he moved his hand to undo the top button and zipper. Castiel grabbed Dean's hand and without breaking their kiss, pushed it away. Dean got the hint and didn't try anything for a while but when he brought his hand to cup Castiel's crotch Castiel pushed at his shoulders and wriggled out from underneath Dean leaving him panting hard, face down on the bed.

"Cas, you always blue ball me," Dean didn't sound mad, just sounded like he was stating a fact. A semi-irritating fact.

"I'm sorry," Castiel pulled his knees up to his chest and tried to bury his face in them, "I just never want to, ever." Castiel mumbled.

"You never what?" Dean had heard him fine but he wanted Castiel to lift his face out of his knees except he wouldn't move his head, just shook it, "I mean Cas, if I don't ya know… if I don't do anything for you that's fine."

Dean actually sounded a little sad. It was one thing to have a boyfriend who was just wary about sex and stuff because it was new; it was another for you to not be able to get your boyfriend horny. Your teenage boyfriend, who you always thought liked to see you swim on the weekends or watch you practice baseball in your tight uniform because you thought he liked the view. Maybe now, Dean thought, maybe Castiel was just humouring him by pretending to be interested in his sport or purposely stayed away from Dean when he was dripping wet in nothing but board shorts. Dean sat back and dropped his hand from trying to wriggle Castiel's head away from his knees.

"I'm sorry that I can't," Dean shook his shoulders and huffed, "get you up." Castiel's head snapped up immediately.

"What? No no no no Dean it's not that. I swear it's not that," well great now Castiel felt like shit. "Trust me Dean, you do things for me. You really do, I just never…," he sighed and shoved his head back into his knees and yelled, "I JUST DON'T KNOW WHAT I'M DOING!"

Castiel felt like a horrible boyfriend, they had been having fun but when he realized Dean was getting something more than study points from it he did react coldly. Sam had once said he was a prude and sort of a tease, but not on purpose. "Not that I want to imagine my best friend doing things with my brother but you are aware you kind of… rile him up and then always stop it right?" Castiel hadn't been aware until Sam pointed it out and now he felt bad. He liked messing around with Dean but whenever it was more than kissing, the fact that Dean was a boy and he was a boy flew into his mind and he became unsure of how things worked and he knew he couldn't ask anyone about it so he settled for pushing Dean away instead of embarrassing himself. Michael would kill him, and then probably stalk over to the Winchester's to kill Dean if Castiel ever asked him about sex. But now Castiel was determined to make it up to Dean.

"I'd probably be more inclined to suck your dick than have sex. That seems pretty straight forward and I've actually thought about it." Castiel stated mater-of-factly, trying to reassure Dean that he did in fact turn him on, but it seemed to only cause Dean's eyes to go wide.

"You've what? You've thought about doing it?" Dean gulped down the air that he had sucked in and pressed his palm to the front of his jeans to will his new coming hard on away.

"Well yeah," Castiel didn't notice just what this conversation was doing to Dean and he went on, "It's just about the only thing I can talk to Anna about at lunch without her knowing exactly what I'm asking. She just thinks I'm inquiring about her sex life, not that I'm trying to learn stuff like how to give you blow jobs." Castiel looked up at Dean who was shaking now.

"Damnit Cas, you can't just say shit like that." Dean flopped back down on the bed and took the blanket he had pulled into his lap when Castiel was talking about sucking his dick and threw it at the wall in frustration; when he did that Castiel noticed the big bulge in the front of Dean's jeans. Normally this would be the moment when Castiel shied away but he had a plan now, to make it up to Dean.

"Why don't you uh… take care of yourself?" Castiel smacked a hand to his forehead at the wording he chose. Dean just snorted.

"I'm not going to go jerk off in your bathroom, I'm fine," he really wasn't though. The denim in his old jeans rubbed up against him in just the right way.

"I didn't say you had to leave," Castiel replied and he had to force himself not to hide his face again.

"Well I'm not making you leave your own room."

"Dean, I didn't say that either." Castiel let his legs drop so that he was sitting with his legs crossed. Dean stared up at him questioning and Castiel gave him a look that confirmed Yes we're thinking the same thing. "I mean if it would help…" Castiel trailed off and waited for Dean's response.

Dean sat up abruptly to bring his lips to Castiel's in a kiss and Castiel leaned forward, halfway into Dean's lap. Castiel laid his hand on Dean's thigh and slid it towards his crotch, experimentally and when Dean didn't object, only moaned in response Castiel let his hand fall into the inside of Dean's thigh, fingertips brushing up against the bulge in his jeans. Dean broke the kiss first but kept their heads together, lips almost brushing against lips as he spoke.

"Are you really serious about this Cas?" Dean laughed a little but really he wanted to know because if Castiel wasn't for this, and would stop halfway through, Dean thought he would explode into a million tiny pieces from all the built up tension.

"Yes," Castiel almost whispered but nodded his head in silence to get his point across.

Castiel placed his hands on Dean's shoulders again, thumb rubbing at the scar through his shirt, as he pushed Dean back's to the bed and shifted to lie beside him and half draped on Dean. They continued to kiss for what seemed like a long time and Castiel was content with that, nearly forgot about the whole plan until his knee moved and brushed against Dean's inseam making him groan at the touch. Castiel trailed kisses down Dean's jaw, barely getting to his neck before he sat up, kept a hand on Dean to signal he was meant to stay lying down.

"Um," Castiel nibbled on his lip again, "Where do you want me?" The question was simple enough but the way Castiel had worded it sent so many scenarios through Dean's mind of just how he wanted Castiel.

"Wherever is fine, just as long as I can see you." Dean offered and Castiel nodded.

Dean started to unzip his jeans and cringed at the deafening sound it seemed to make in the quite room. He didn't take himself out, just opened up his jeans enough for him to stick his hand in there and fist himself. When Dean first touched himself he moaned, eyes fluttering at being touched finally and when his eyes filtered open again Castiel was watching him with his ever present intense stare and, fuck that was hot. Castiel wasn't exactly sure what he should be doing but apparently catching Dean's eye every once in a while seemed to work out fine for the time being. Dean worked his fist faster, twisting a little when he dragged his hand upwards towards the head of his cock; he locked eyes with Castiel while he did this, his breathing getting heavier now.

Castiel watched the way Dean move his hand within his pants and the way Dean screwed his eyes shut, biting down on his lip every other stroke and the way Dean's neck was straining and he was sweating. The movement of his hips shifting off the bed and the noise that broke from Dean's lips went straight to Castiel's gut as he raked his eyes up Dean's body to settle on his face, look him in the eyes again. The sounds Dean was making started pounding in Castiel's head and suddenly all he could think of was if he could be the one that caused them to come out of Dean, What if that was my hand on Dean? Or my mouth or just me?

"Cas," Dean's voice sounded broken and full of lust and that was all it took. Castiel moved over to Dean hesitantly at first as he leaned down and kissed him, tongue flicking out to wet Dean's lip before he bit it hard. Dean moaned loud, hand picking up pace and used his free hand to pull Castiel onto him. Castiel trailed his hand down Dean's arm and shoved it into his pants alongside the hand that Dean was using to jerk himself off with, he just moved his hand along with Dean's for a while before Dean moaned Cas again and Castiel shoved his hand out of the way completely. Castiel wrapped his hand around Dean's cock and very nearly said aloud just what he was thinking, "Holy shit I have Dean Winchester's dick in my hand," but Dean had moved his newly free hand to grip Castiel's ass and that was a pleasant surprise that stopped all train of thought. Castiel kept his hand at the same pace that Dean had been moving at and continued to kiss him hard, sucking Dean's tongue into his mouth. Dean's hips surged off the bed so that he was now fucking into Castiel's hand, the hand Dean had on Castiel's ass tightened causing Castiel to jolt in surprise, his thumb pressing into the slit of Dean's cock and Dean came as Castiel trailed kisses down his neck, sucking a bruise on his collar bone. Dean lied there for a moment, catching his breath when he realized Castiel's hand was still wrapped around his dick, twitching as if to still jerk him off, Dean reached down to pull Castiel's hand out of his jeans. Castiel looked at his hand, covered in Dean's come and wasn't exactly sure what to do; he wanted to go wash his hands but thought getting up and leaving the room soon after what happened was not the thing to do so he just looked at his hand as if his stare would clean it. Dean chuckled and pulled off the t-shirt he was wearing, didn't really like it all that much to begin with, and handed it to Castiel to use as a towel. When Castiel was done, had thrown the shirt on the floor he turned over on his side to face Dean, who was now lying on his side as well.

"So," Dean began hesitantly, "I assume you liked that?"

"When can we have sex?" Castiel blurted out and he looked into Dean's eyes like he was dead serious and Dean had to laugh at that.

"Later. That's for later." Dean pressed a soft kiss to Castiel's lips and Castiel pushed his body up against Dean's, moaning when the hard on he had pressed into Dean as Dean pulled Castiel's body closer.

"Oh so I see I do get you going!" Dean edged closer to him.

"Dean, I told you, you did. Why didn't you believe me?" Castiel buried his head into Dean's neck a little embarrassed.

"Guess I just had to see it," Dean pushed Castiel back a little bit, looked at strain in his slacks biting his lip, "to believe it."

Dean pushed back and got up to sit back down in the midst of their books, picking up one of them so he could pretend to read it. Castiel moved to get up to, tried to rearrange himself so that his erection didn't bother him. He hadn't expected anything from Dean, well he didn't expect to be turned on so much by watching Dean but he still didn't expect Dean to reciprocate since they entire thing was for Dean. Castiel must have been staring down at his crotch for too long because Dean laughed and shook his leg.

"Need help with that," Dean wiggled his eyebrows and pointed to Castiel's crotch.

"But I don't need—"

"Yeah, sure" Dean murmured as he closed the distance between them, lips brushing up against Castiel's jaw, handing sliding up his thigh only to stop right before Dean would have been touching Castiel. He sat back quickly and looked at Castiel with a little tugging at the corner of his lips.

"How good are you with waiting Cas?" the smile threatened to get bigger.

"I feel I'm fairly good at it." Castiel knew where this was going and now he hated himself for being a sort of prude and tease.

Dean surged forward, hand cupping Castiel and lips crashing together making Castiel moan and arch into Dean's entire body, panting hard. He almost pulled Castiel into his lap, hands hovering over his hips before he broke free and grabbed one of the books.

"Let's get back to studying," Dean boomed cheerfully.

Dean thought he was playing dirty, giving Castiel a taste of his own medicine but Castiel realized he really only needed Dean to answer one question right before he could climb into Dean's lap. Because once that happened Dean would forget about teasing Castiel because Dean was a teenage boy who would have his very needy boyfriend in his lap.

"What is the ultimate power source for the chemical reactions in life?" This was easy; Dean could get this one right.

"No clue Cas," Dean smiled and shrugged his shoulders.

"I am going to kill you," Castiel whispered, didn't intend for Dean to hear it.

"But if you kill me then you'll be spending more than the second half of the summer alone."

"What is the numerical value for Avogadro's Number?" Castiel had never wanted Dean more.

"Dude, avocados have numbers? Unreal," Dean was having too much fun with this now that the tables had turned.

"Oh come on Dean, I know you know that one because your class had a party since it represents a date."

"I have no idea what you're talking about man." Castiel sighed and tried to collect himself.

"What are the three basic components that make up an atom?" Come on, he whined in his head.

"Uh, earth, wind and fire?" Dean looked dumbstruck and bit down on his lip. When he released it his lip suddenly filled with blood and plumped out and Castiel wanted more than anything to catch it between his own teeth. Dean noticed Castiel looking directly at his mouth and continued to draw his lip into his mouth, sucking on it a bit before letting go and pouting.

"These questions are really hard Cas, I don't know when I'll get another one right."

"Dean Winchester." Castiel gritted out, staring daggers at him.

Dean just leaned forward, put his chin in the palm of his hand and looked innocently up at Castiel, who was gripping his knees and body shuddering. Dean's knees were touching Castiel's and he brought the hand that his chin was not rested in and started drawing circles with his finger on Castiel's kneecap.

"Yes, Castiel Novak?" hand inching away from Castiel's knee and towards his inner thigh.

"How many protons does hydrogen have?" Castiel drew in a shaky breath and looked at Dean like he was about to slaughter him if he didn't give the correct answer.

"Hmm that's a very good question. I wonder how many protons hydrogen has." Dean said it as if he was pondering the meaning of life and tilted his head up to the ceiling, bringing the hand on his chin up to stroke his neck. He was doing that for Castiel, on purpose and Castiel knew it.

"Dean!"

"One. Okay, hydrogen has one pro—" Castiel launched himself from the sitting position he was in and pushed Dean backwards on the bed, quickly scrambling up his body and pressing his lips to Dean's before he could even finish his sentence.

Dean started laughing, about to make a joke, but when Castiel set his legs on either side of Dean and rolled his hips Dean gasped and jerked forward. Okay this was more like it. Dean gripped behind Castiel's knee and flipped them over, keeping Castiel's legs on either side of him so that when he pressed down his hip moved against Castiel's hard dick. Castiel instinctively wrapped his legs around Dean's waist and was rewarded greatly when the minor bulge in Dean's still undone jeans brushed up against the soft fabric of Castiel's slacks causing Castiel to stifle a moan around Dean's lips when Dean moved his hips, pushing hard into him.

Dean rolled his hips again making the hand Castiel had on Dean's bare back grip and dig half-moons into his back, Dean repeated the motion a few more times before Castiel broke the kiss to gasp and chant out Dean's name as he was thrusting upward helplessly trying to come. Dean eventually moved his hand down between them like before, but hesitant.

"Are you to actually let me touch you this time?" Dean teased and was repaid with Castiel digging his hand into Dean's scar, which always seemed to be a pleasure point for him. His hand grabbed Castiel through his slacks and this time he did everything but try to squirm away from Dean. Castiel bucked his hips up and still rocked up and down against Dean's body. He withdrew his hand and Castiel clenched his legs around Dean, groaning in disapproval until Dean settled his hand back down with a chuckle. Dean broke the kiss as well, placing kisses all down Castiel's neck, undoing the first four buttons of his shirt, trailing kisses and flicking his tongue out against the skin as he moved further and further down and catching one of Castiel's nipples, tugging slightly.

"Dean," Castiel gasped out and gripped the back of Dean's head. He wasn't sure if he wanted to pull him away, push him in or some weird combination of both but it was good. He pulled his head away and kissed back up to Castiel's mouth, pressing his body into Castiel again and again, rocking with the movements of his own hand until Castiel was gasping and moan very loud around every kiss. Thank God no one was home. Dean's tongue whirled lazily in Castiel's mouth a few more times before he moved his head to suck a bruise into the skin on Castiel's neck, hand pressing harder and faster. Castiel wrapped his arms around Dean, held his body tight to his own as his hips jerked helplessly when he came. He was still holding Dean to his body well after he rose out the aftershocks and returned to kissing the scar on Dean's shoulder before rubbing Dean's back in a way that said they should probably detangle themselves before someone decided to come home.

"Okay," Castiel said pointedly as he buttoned his shirt up again, "Let's get back to studying for real this time because the final is next Tuesday." Castiel began arranging the books into a neat pile to his left and grabbed his notepad. Dean sat shirtless in front of him, but now instead of the whole bed separating them they were practically on each other.

"Ugh do we really have to study more? It's Sunday and the final is next Tuesday so technically I have a whole nother week to do this." Dean drew his hand lazily up Castiel arm.

"But Dean," Castiel leaned into Dean's side as he spoke, head dipping down to his shoulder, "now there will be new incentives for study time."

He sucked on the edge of Dean's scar and Dean hummed with approval, a shudder going through his body.

"Deal and I vote we study every day until the test."

"Alright, we can but the incentives only count when no one's home. Or at least when Michael isn't home."

"Yeah, you're loud." Dean teases but Castiel just smiles and leans in to kiss Dean again.