AN: I was watching A Thin Line Between Love and Hate and the scene where Martin Lawrence' s character is explaining the rules to his friends inspired me to write this. This is the first story that I'm publishing and criticism/reviews are totally welcome. This is gonna be slash so if that's not your thing, you don't want to read this one.

Disclaimer: I do own Criminal Minds or any of its characters. The only thing that belongs to me is a very vivid imagination.

Contains mild spoilers for "Derailed" "The Popular Kids" "Somebody's Watching" "The Boogeyman" "Sex, Birth, Death" "Profiler, Profiled" "Revelations" "In Name and Blood" "Lucky" "Mayhem" "Minimal Loss" "The Instincts" "Memoriam" "Brothers in Arms" "Amplification" "Conflicted" "To Hell…and Back" "Nameless, Faceless" "100" "Our Darkest Hour" and "Our Longest Night".

Prologue: Strange What Desire Will Make Foolish People Do

Derek Morgan was fucked. He threw a covert glance across the aisle at Spencer Reid and saw that the young genius was wearing an expression that left no doubt should Derek even attempted to speak to him all hell would break loose. So Derek stayed on his side of bullpen, playing back the events of the past few months in his head and trying to figure out how he was going to get out the situation he currently found himself in. The situation that he had created.

Derek had known better. He knew every play in the Player's Handbook by heart, hell he'd even authored a few of the chapters. Derek didn't just play the game, he was the freaking MVP. It wasn't surprising that Derek never found himself lacking for company. He was extremely attractive and his chocolate brown skin, warm brown eyes and tall, muscular frame that housed bulging biceps and picture perfect abs pretty much guaranteed that when he walked into a room, he would be the center of attention . In truth, Derek looked more like the leading man on some daytime drama instead of an FBI agent who made a living profiling some of the most dangerous people in the country. While his looks made it easy for him to capture someone's attention, it was the sheer force of Derek's personality that allowed him to keep it. He was charismatic, charming, and confident. His smile was like turning on the sun, and his laugh was a pleasant, melodic sound that hinted at hidden depths and soothed the soul. Derek flirted like it was as natural as breathing and he knew just how to get someone eating out the palm of his hand. Derek knew who he was, what he had to offer and what he wanted, and it was that combination of good looks, personality and confidence that many people found impossible to resist.

As sure as he was of what he did want, Derek was equally sure of what he didn't want, and what he didn't want was a relationship. He didn't want to be tied down, he didn't want to open himself up to the scrutiny of someone else, someone who might have the power to tear him to pieces. Derek had worked too long and too hard to build himself back up to ever hand over that type of power again to anyone. Derek liked things nice, uncomplicated and easy. To keep them that way Derek didn't date, but he did hook up. A lot. His boys would always ask him how he managed it, to get in, get what he wanted and get out without a bunch of drama or looking like a dog.. He would always tell them that the secret to his success was that he always obeyed the rules of the game. Never lie. Always let it be known you aren't exclusive. Don't do "relationship" things so there is no expectation of monogamy, (Derek Morgan did NOT want to meet your mama). Most importantly, obey two of the most fundamental rules of the game: Don't play where you stay and don't play where you work.

Simple rules really and Derek adhered to them like they were the gospel. He never took anyone to his place, he never created expectations beyond good company and great sex. He never pretended he wasn't seeing other people and as far as his workplace went…Derek never, repeat, never, hooked up with anyone from the office. Derek had been tempted over the years…a mail clerk here, an agent there, that temp in human resources…but he never violated the rules of the game. He knew better. And he'd never wanted anyone badly enough to take the risk. Or at least he hadn't…until Spencer Reid.

If someone had told Derek back when he first met him that Spencer would be the reason Derek lifted his self-imposed ban on office romances, he would have laughed in their face. When they first met Derek had thought Spencer looked like the bastard child of Mr. Rogers and Steve Urkel. His brown hair was parted down the middle and then gelled within an inch of it's life, confined to his scalp like a prisoner of war. He had on a pair of glasses that Derek swore had a co-starring role in Revenge of the Nerds, a pair of dark brown cords that were a little too short and revealed that Spencer was wearing mismatched socks, one blue, one yellow. His white dress shirt was rumpled and stained with both a smear of jam and a spot where he'd spilled some coffee on it. Spencer was also wearing a cardigan that Derek was sure he'd stolen from some 80 year old man. Spencer's entire appearance had left Derek wondering if the kid even owned a mirror. Then Spencer had opened his mouth to speak and good Lord, Derek was sure the kid was going to run out of oxygen if he didn't stop and take a breath. Derek concluded that Spencer Reid might be a genius hand picked by Jason Gideon for the BAU and the future of the unit, but the kid was a stuttering, poorly dressed, wet behind the ears hot mess. If you'd told Derek back then he would come to regard Spencer as the living embodiment of temptation, he would have asked you what you were on.

It wasn't until they'd been working together for a couple of years that Derek noticed Spencer. Not the terrible clothes, not his intelligence, not his tendency to talk at warp speed about things Derek wasn't sure even existed, or his seemingly endless fountain of compassion and empathy, but Spencer. And what he saw made Derek stop, stare and released a coil of smooth heat that uncurled inside of him and went straight to his groin with enough force to make him close his eyes and take a deep breath.

Derek wasn't sure when it happened. He suspected his initial impression and growing closeness with Spencer had somehow blinded him to the changes in the young man. It took a Hollywood starlet dragging Spencer into a pool and making out with him for Derek to take a second look at Spencer and see what he'd been missing.

Spencer was gorgeous. He had wide hazel eyes, soft full lips, high cheekbones and alabaster skin that just begged Derek to nip, bite and leave a mark. He had the hands of artist, slender and graceful. The more Derek looked at them the more he decided Spencer's hands were downright sinful. Spencer would use them to illustrate his point as he talked, arching them through the air with child like exuberance or to keep pace when he was reading, his long, elegant fingers caressing the page, making Derek irrationally jealous of whatever Spencer was reading because he wanted those fingers caressing him. Spencer was tall and lean, built more like a runway model than a field agent, and try as he might to tame it, his hair was a perpetual avalanche of brown silk, framing his face and sending out a silent invitation to be touched and tousled. And oh how Derek wanted to touch.

But he wouldn't. He couldn't. There were rules. Not just his rules, but FBI rules to consider. It wasn't worth jeopardizing both their careers, plus the team if things went badly. Then there was his privacy to consider. He didn't exactly broadcast his bisexuality. Derek Morgan was not going to be wearing rainbow colors and marching in a parade anytime soon. As far as Spencer went, he'd spent enough time with him to know that while the kid described his own sexuality as "fluid" he had no practical experience. Sex for Spencer would have to be about more than giving and receiving physical pleasure and surface level emotions. It would be deep, meaningful, and something he'd view as a bonding experience. And THAT was something Derek just couldn't offer and as attracted to him as he was, he liked and respected Spencer as a person too much to take advantage of his youth, his inexperience and his need to belong to someone. So Derek put his attraction out of his head and decided he'd just be there for Spencer.

Over the years being there for Spencer became one of Derek's top priorities. He was there when to listen when Spencer needed to talk about Dr. Bryer and what happened on that train down in Texas. He was there to assure Spencer that Hotch hadn't meant any part of what he'd said to him when they were trapped in the ER by Phillip Dowd and that it was ok to be confused about his feelings about taking a life. He was the one Spencer called when the nightmares got so bad that he was afraid to fall asleep. When Elle left, Derek was the one who held Spencer when he cried and the only one Spencer believed when he told him everything would be ok. He was there to put Spencer back together when he was paralyzed by guilt over how things had gone down with Nathan Harris. He was the one who slept on Spencer's couch to help keep the nightmares at bay after Hankel. He was the one Spencer came to, at three in the morning, tears streaming down his face, glass bottles in his hands, desperation in his eyes begging for help to detox. He was there to hold Spencer together when Gideon left and he was there to keep Spencer from drowning in guilt over how things went down when he and Emily were trapped in that compound with Cyrus. He was also there to pin Spencer against a wall and tell him that if he ever again did what he'd done with Owen Savage that there wouldn't be anything left of Spencer for Hotch to fire because Derek was going to kill him. Their bond was strengthened when the kid was afraid his father was a pedophile and a murderer and Derek and Rossi stayed behind after a case in Vegas to help Spencer find the truth. Derek was Spencer's rock in the aftermath, when he'd found that while his father may not have been a murderer, he was a selfish coward who left his ten year old son and schizophrenic wife to fend for themselves while he lived ten minutes away doing absolutely nothing to help. For Spencer, finding out that cyber stalking him was the extent of his father's interest in his life was almost worse than thinking the man a killer and it was all Derek could do to keep Spencer on level ground in the weeks and months that followed. When Spencer got Anthrax, Derek was the one who sat vigil by his side in the hospital and offered up his guest room for weeks so he'd be there for every step of Spencer's recovery. Derek was the only one Spencer told about calling in favors to have Adam Jackson transferred to a facility in DC so Spencer could visit on a regular basis. When Spencer got shot in the knee, he bunked in Derek's guest room yet again so he wouldn't have to worry about navigating the stairs at his apartment complex. Whatever Spencer needed, whenever Spencer needed, Derek was there.

As much as Derek was there for Spencer, Spencer returned the favor. After the team found out about Carl Buford, Spencer was the one person who didn't try to make Derek talk about it. He was simply there, with take out and card games and magic tricks and mindless action movies. Spencer was the one person that didn't look at Derek with pity…and that meant more to Derek than he'd ever be able to say, and that was the reason that when Derek did talk about it, he talked to Spencer. When Hotch confronted Derek on his trust issues, Spencer listened to Derek rage and then calmly, quietly told him that he understood how hard it is to trust people after you've been betrayed, but going through life with a closed fist meant no one could ever hold your hand. When Derek was conflicted about faith, Spencer was there to listen, with no judgments and no pressure, assuring Derek that whatever he decided, Spencer had his back. When a case where the UnSub was a cop killer frayed Derek's nerves and pushed him to his limits, Spencer was there to talk him down and help him decompress. When the team made it back from Canada, after being confronted yet again with absolute proof that true evil does exist in the world, Spencer was there. He invited himself over to Derek's and without a word, opened Derek's refrigerator and began to rid it of any and all pork products, then, while Derek showered, made a hushed call to his mother and told her that it might be a good idea to give Derek a call and remind him that there was still love and light in the world. When the nightmare that was George Foyet took over all their lives, Spencer was the one Derek leaned on. When he was wracked with guilt over Det. Spicer's death and confused about what to do with Ellie, Spencer was there, telling Derek of his absolute faith in him and that if he needed to fall apart it was ok because Spencer would be there to put him back together. And when Derek did fall apart, Spencer was solid and sure and Derek had never been more grateful for anyone, or anything in his life.

Derek was grateful, appreciative, protective of Spencer and the friendship they've built. The temptation to push it further, to make it more is ever present, but Derek never let himself go there. He can't break his rules and there's no reason to. The rest of the world seems to be oblivious to Spencer's charms. In all the years that he's known him Spencer's been on one disastrous date with JJ and one equally disastrous date with some guy Garcia set him up with. So Derek settles into what they are, pushing his attraction aside, safe in the knowledge that he and he alone knows just how special Spencer Reid is.

Derek let his mind wander back to the night that led him to this place, the night his bubble was violently, publicly and viciously burst. The team had decided to hit their favorite bar after work. Spencer had tried to beg off, but Derek cajoled him into joining them, pointing out that even Hotch was coming. The moment they hit the bar, Derek got dragged out onto the dance floor. The vibe was good, the music was good and the two ladies pressing themselves indecently up against him were even better. Derek had been on the floor for awhile, when he looked around the bar to see where his team members were.

Garcia and Kevin were on the dance floor with him, doing things that gave him an all too clear picture of what went on in their bedroom. Rossi was at the bar, surrounded by nubile young things, trying to pass at least one the contenders off to Hotch who was looking horrified by the prospect of having to entertain one of Rossi's groupies. Prentiss had eyes on the bartender and was laughing and flirting her way to a possible walk of shame the next morning. JJ was in the back schooling Will and some of the DC's finest on darts and Spencer was…oh HELL no.

Derek's blood ran cold then began to boil. His hands clenched and his eyes narrowed. Spencer was at the opposite end of the bar from Hotch and Rossi, leaning against it slightly, sipping on his club soda, and laughing at something the guy he was talking to had just said. Derek took a closer look at Spencer's companion. He was taller than Spencer, with an athletic build and close cropped blonde hair. He had blue eyes and when he smiled down at Spencer he revealed he had perfect white teeth and even more perfect dimples. The guy stepped slightly closer to Spencer, whispered something in his ear and moved his hand down to the small of Spencer's back.

And just like that, Derek was on the move. Derek didn't stop to think about why he was leaving two hotties who all but promised him a threesome standing alone on the dance floor. He didn't see Garcia nudge Kevin and jerk her head in his direction and then point to Spencer at the end of the bar. He didn't see Kevin hand his girlfriend a twenty dollar bill and break out into a huge grin. As Derek stalked his way toward Spencer, he didn't acknowledge Rossi's smirk, Prentiss' knowing smile, or spend too much time to trying to figure out why Hotch looked like he was about to go medieval on someone. All Derek could see was Spencer and all Derek could focus on was getting that guy the hell away from him. In the moment it took for Derek to put his hand on Spencer's shoulder and give Spencer's new found friend a look a look so scathing that it had the man stuttering his goodbye and making a hasty retreat, Derek had made a decision. He had decided that he'd waited long enough. That he would be damned if he let some stranger in a bar have what he'd been fantasizing about for years. That if there was a line, he was going to cross it, take Spencer with him and damn the consequences.

One moment. That was all it took to get Derek on the path towards self-destruction.. A moment of clarity, or a moment of weakness, he wasn't sure which, but it damned him all the same. Derek had decided in that moment that he wanted Spencer and Derek Morgan was a man who got what he wanted. He'd gone after Spencer knowing full well that he would get him and ignoring the little voice in his head that told him that Spencer would want, would need more than Derek was used to giving. Derek had told himself they'd cross that bridge when they got to it, that the fall out wouldn't be that bad, that the risk would be oh so worth the reward and that he'd be able to make Spencer understand that they could be good friends who had great sex and it didn't need to be anything more than that. Derek convinced himself that he could have Spencer in his life and in his bed without making any major changes to his current lifestyle or causing Spencer any unnecessary emotional distress.

Looking back on it now and taking in his present situation, Derek almost, almost, wished he could take it back. That moment, that decision to give into temptation was the reason Derek found himself sitting at his desk, sneaking glances at Spencer who was steadfastly refusing to even acknowledge the older man's presence. To make matters worse, the team was making no secret of their interest in the drama playing out in the bullpen. Garcia kept sending him emails demanding to know what he'd done to her Junior G-Man, Prentiss was trying (and failing) to solicit information out of Spencer, Rossi had stopped by Derek's desk under the guise of needing his help with a case file no less than five times in the past hour and Hotch…Hotch had come out of his office exactly once but it was enough. Hotch had looked at Derek, his face cold, hard and implacable, and Derek had received Hotch's unspoken order: "Fix this." Derek wanted nothing more in that moment but than to fix it, he just had no clue how.

Before any of this ever got started Derek had known better. What Derek knew now, sitting in the rubble of the emotional bomb that he set off, is that he is completely, totally, and thoroughly fucked.