A/N: Time for the first of two chapters of back-story. This one contains lemon- ness! (Oh and yes, it is the same potion that was used in my KomuixReever story "Pheromones." And sections of this may not be very good because I was trying to work thorough my nausea.)

In the beginning, it had been an accident. Komui had been testing out one of his concoctions and Kanda and Allen had been unfortunate enough to be in the vicinity. It was supposed to make people get along, but only as friends (to keep guys away from Lenalee).

Instead, it had been an aphrodisiac and they'd fallen victim to its effects. They had tried to move on, away from that incident, but it had been rather… difficult.

Kanda had had a hard time dismissing the images of a flushed and panting Moyashi writhing beneath him.

Allen was having a hard time too. Kanda had just been so dominant and … possessive. In a good way. He was still trying to reconcile that side of the samurai with his previous impression of who Kanda was.

But in the end it had been a mistake. Neither of them had been in their right mind. Plus they'd been trapped together so neither of them had gotten to chose their partner. Kanda highly doubted that he would've been Allen's first choice, and honestly he might not have been. That thought pissed him off almost as much as the fact that he actually cared.

Allen had always looked up to Kanda in some weird way and yeah, he sort of had a crush on the samurai. Even so, he'd never been able to imagine something like that. He'd always stopped himself from trying. He knew it would never end well and besides, Kanda hated him.

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Kanda and Allen had been called into the Supervisor's office for a mission briefing.

Komui had lured them into another room claiming that he had a 3D model of the city he was sending them to, and that looking at it might help. They were told to go inside and sit while he got more coffee. It was a trap. As he shoved the exorcists inside and slammed the door behind them, Komui sprayed some water or something (i.e. pheromones) on Allen. They could hear the Supervisor laughing manically as he took off.

Both teens shuddered before assuming positions on opposite sides of the room. They didn't even try the door, they knew it was useless. Allen paced restlessly while Kanda sat and polished Mugen. The samurai refused to be a test subject, especially not robot bait, which was highly likely at that point.

The potion, which was specially formulated to get stronger over time, slowly diffused into the air.

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Allen could feel Kanda glaring at him and figured that his ceaseless fidgeting was the problem. It wasn't.

The truth was, Kanda couldn't stop staring at the Moyashi, and it was really starting to piss him off.

Allen slumped against the wall, his head dipping back as he sighed. It was too damn cute. Kanda lunged.

Allen straightened up just in time to see Kanda coming right at him and for a second he seriously thought he was going to die.

But then Kanda was kissing him. It was surreal… but good. And for some reason he didn't even think of trying to run away.

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Kanda couldn't help himself but he had no idea how long he had been holding himself back.

He knew he was being too forceful but the small mouth beneath his was just so soft and sweet.

Allen had realized that Kanda would never do something like that of his own free will. He must have been drugged… they both must have. It would explain a lot. But if that was the case then it was okay right? It wasn't either of their faults and it wasn't like Kanda was taking advantage of him… so he didn't even try to fight it.

Xxxx

Kanda had been expecting a struggle and was surprised when none came, but just to be sure he pinned Allen's hands up onto the cold wall behind him, the same wall that was digging painfully into the smaller boy's back and shoulders.

He pulled back to examine his captive, taking in the delicate blush on Allen's cheeks and the way he shyly averted his gaze. It was too much. The pheromones were affecting his brain, making him even more brash and aggressive than normal.

Later, neither of them could recall the exact progression of events after that. There was more one-sided kissing as Allen's confused and weak attempts to reciprocate went largely unnoticed.

It bothered Kanda that Allen was being too compliant, too silent. He attacked the boys neck trying to elicit some sort of response. It had the desired effect. Allen mewled and knocked his head back against the wall.

One of Kanda's hands dragged off Allen's pants and underwear while the other gripped the boy's wrists hard enough to leave bruises.

Allen was suddenly aware of just how cold the room was especially the floor; it was a sharp contrast to his body, which felt like it was on fire. He whimpered.

Kanda smirked evilly. He held two of his fingers up to the Brit's lips and upon getting a confused look, simply pushed them into the boys mouth. Allen finally caught on and started sucking on them. Then Kanda's self control was truly put to the test.

He pulled his hand away from the far too tempting mouth and flipped Walker onto his knees (while pulling him back so that the boy's face wouldn't collide with the wall).

Allen winced as the first finger was roughly thrust into him, but he gritted his teeth and bore with it, he'd heard that it could be much worse.

Kanda set about preparing Allen as quickly as possible, impatient for what was to come. After a minute or so he added the second finger, pausing there for a second before beginning to scissor them.

Allen had finally gotten used to the weird feeling when Kanda deemed him ready and pulled away, making him whimper at the loss.

The fingers were quickly replaced with something much larger. But Kanda was at the limit of his generosity and gave Allen no time to adjust as he began to rapidly fuck the boy, pulling almost all the way out before slamming back into the tight heat that encased his cock.

Allen couldn't breathe, only pant and mewl. And his body, which wasn't used to any kind of physical contact was quickly over stimulated, by the furious assault on his prostate as well as simple sensation of Kanda's skin against his was quickly sending him over the edge. And then Kanda's hand brushed his neglected cock. His vision went white as he moaned pathetically and came, his arms giving out as he collapsed onto the floor.

But Kanda wasn't finished with him yet. He sunk into the clenching velvety walls a few more times before finding his own release with a low primal growl, claiming his Moyashi.

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And then reality hit like a ton of bricks. Something clicked in Kanda's brain, Allen hadn't wanted to. It had been the drug. So… He pulled away quickly and fixed his own clothes. The Moyashi was going to be furious with him so he might as well face it as a (fully clothed) man.

But instead, when Walker finally gathered the strength to look at him, instead of anger, tears were threatening to spill from the boys eyes . It wasn't like Allen had expected a cuddle and an "I love you" but he hadn't been expecting the samurai to come back to his senses that quickly. He felt really lonely but he couldn't explain why.

"Don't look at me like that! It's not like I wanted to…" Kanda broke off and left the room, horrified to find that the door had been unlocked the whole time.

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After the "incident", they had both gone their separate ways on missions, and pretended that nothing had happened.

In truth, as time passed Kanda wasn't sure that it had happened at all. Allen didn't act any differently around him, and there was no way the Moyashi would ever let him… or that the boy's vocal chords could even make those noises. Hell, maybe Komui had come up with some weird daydream drug or something and he had imagined the whole thing.

A/N: The next chapter will continue the flashbacks and have them getting together to begin with, and it will be more humor and less angst.

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