Ok, so maybe you don't know all of what happened next. This happened later that night, after the Tamaki x Haruhi drama.
Kaoru laid in bed thinking about what had happened earlier that night. He wasn't sure how to tell Hikaru, but his brother needed to know.
"Hikaru, are you awake?" Kaoru asked softly.
"Yes, why?" he asked sleepily.
"I need to tell you something." Kaoru answered sheepishly.
"Can it wait until morning?"
Kaoru thought about it and decided that it could wait. "I guess so."
"Okay, tell me when we get up, goodnight Kaoru."
"Goodnight Hikaru." Even though he said this he still wasn't sleepy. "I wonder if Kyouya is asleep yet."
Kaoru got out of bed and snuck out of the room so he didn't wake his brother. Once in the hall he began walking to his boyfriend's room. When he reached the door he knocked gently.
Footsteps could be heard from within. The door opened to reveal a shirtless Kyouya. "Hello Kaoru-kun." He smiled.
"Hi Kyouya-kun, may I come in?" Kaoru smiled softly.
"Of course, may I ask why you're here?" Kyouya moved to allow Kaoru entrance.
"I'm not sure. I couldn't sleep and wanted to see if you were asleep yet." Kaoru explained as he entered the room.
"Well I'm not, in fact, I was wondering the same thing about you."
"Yes, that and whether or not you had told Hikaru about us." Kyouya blushed a bit.
"I tried but he was tired and thought that it could wait until morning." Kaoru explained
"That's fine, as long as he finds out soon; I'm not what you'd call an exhibitionist and I rather he not walk in while we're making love." Kyouya stepped close to Kaoru, took him in his arms, and kissed him in one fluid motion that gave Kaoru little time to react.
All the red-head could do was melt in the arms of his beloved sempai. Kyouya walked Kaoru back until he was pressed against the wall. The raven haired boy grabbed his boyfriend's wrists and pinned them to the wall above the boy's head giving himself and slight sense of déjà vu. He then laced their fingers together and came up for air. "Do you think Hikaru will come looking for you?"
"No, seeing as he's sound asleep." Kaoru answered breathily.
"Good." Kyouya swept Kaoru over to his bed and hovered over him, again with the sense of déjà vu.
Kyouya kissed Kaoru then started to kiss and nip his way down to his boyfriend's navel. He lifted his head to give a look that was asking his partner for permission to continue. Kaoru nodded gently.
Kyouya slid off the pajama pants that the red-head wore, taking the boxers with them. He tossed the clothes behind him, not really caring where they landed, then removed his own. The raven haired by kissed his way up the inside of Kaoru's leg until he came to the boy's stiff member.
Kyouya gave the tip a quick lick before engulfing it, and causing Kaoru to gasp. The Shadow King sucked gently, which earned him a few delicious moans, and then began licking the red-head's cock like it was a long and tasty lollipop. Kyouya gave the tip one last lick before making his way back up Kaoru's body, stopping at his nipples to give them each a lick and a nip then kissed his boyfriend passionately.
"Kyouya-kun, please stop teasing me so much." Kaoru said breathily.
"As you wish." The Shadow King smiled and brought three fingers up to Kaoru's mouth. "Suck."
Kaoru happily did as he was told. He sucked and licked his sempai's fingers, which caused the older boy's member to harden even more, if that was possible. Kyouya took his fingers out of Kaoru's mouth with a pop, a string of saliva still connecting them.
Kyouya placed Kaoru's legs on either side of his hips and slid two fingers into his boyfriend knowing that that he'd still be stretched a bit from their earlier meeting. It didn't take long for the Shadow King to find Kaoru's sweet spot. When the red-head let out a gasping moan the raven haired boy smirked and added a third finger.
When Kyouya felt that Kaoru was stretched enough he removed his fingers, earning him a sound that was somewhere between a groan and a whine. The older teen leaned over his gorgeous lover and gave him a heated kiss as he positioned himself.
With a single thrust Kyouya was fully seated within Kaoru and had to restrain himself from pounding his beloved into oblivion. The Shadow King waited for Kaoru to once again get used to the feeling of having Kyouya's hot member so deep inside him.
The red-head began to squirm. "Move Kyouya-kun."
He did as requested, starting with long, slow, and languid thrusts. Kaoru could tell that it took most of Kyouya's strength to be so controlled and got an idea in his devilish little mind.
When Kyouya rose to sit on his knees Kaoru rose with him and wrapped his arms around the other's neck. The Shadow King was intrigued.
"Kaoru-kun, what are you…" he stopped mid-sentence when he felt his boyfriend's hot breath on his ear and warm tongue licking the shell.
"You're wasting so much energy by holding back; we are on vacation, now let me have all you've got." Kaoru whispered seductively.
"I don't want to hurt you."
"You won't, I trust you, besides, I want to know just what you're holding back." The red-head smirked.
"You asked for it." He returned the smirk and just as Kaoru was about to lay back down Kyouya caught him, unsheathed his member, turned Kaoru around, and re-sheathed himself. The raven haired teen held the red-head's hips tight and began to thrust fast and hard.
Kaoru grasped the bed sheets as though they were the only things keeping him from floating to heaven. The feeling of Kyouya mercilessly driving into him and hitting his sweet spot every time was beyond words.
All that could be heard was the sounds of two boys panting heavily and of sweat slicked slapping skin. As the minutes went by the two drew closer to their ends.
"Kyou…ya…so…close." Kaoru breathed out between thrusts.
"So…am…I." Kyouya reached around and began stroking Kaoru's swollen member in time with his thrusts.
"KYOUYA!" Kaoru cried as he came hard.
"K-KAORU!" Kyouya followed when Kaoru's walls contracted around him.
The two of them collapsed on the bed and slowly came down from their respective highs. Kyouya pulled out of Kaoru and rolled to the side taking the boy with him.
Kaoru turned over to face Kyouya. "That was amazing."
"Indeed it was." The Shadow King smiled.
Kaoru was just about to curl up next to Kyouya when the door opened and Hikaru walked in.
"Hey Kyouya-sempai, have you s-seen…" It took a moment for Hikaru to take in the sight before him. "I take it this is what you wanted to tell me about."
"Yes." Kaoru nodded. "I wanted to tell you that I'm in love with Kyouya-kun."
"I see," Hikaru looked at his sempai. "Do you love him back?"
"Good, then I'll see you two in the morning. Goodnight Kaoru, sempai." With that Hikaru left the room and closed the door.
"We may have some explaining to do." Kaoru looked to his boyfriend.
"Yes, but that will wait until the morning, for now we sleep." Kyouya pulled Kaoru close.
Kaoru settled into the embrace. "Goodnight Kyouya-kun."
"Goodnight Kaoru-kun, I love you."
"I love you too."