Poison.

Epilogue:

It was fifteen years later, and Sirius was sitting at the table in his parents’ house, having been on the run from Azkaban for the past two years. The house was damp and musty and reminded Sirius of a time he would rather forget.

He was stuck living in this hole because of the Ministry looking for him and the Death Eaters knowing what he was. And he hated it! Almost as much as he hated the greasy haired Slytherin that currently shared the house with him.

Sirius' thoughts were suddenly interrupted by the devil himself. "Black… Are you going to sit there moping all day, or do something useful for once?" Snape sneered from the doorway.

"Piss off!" Sirius replied, flicking an old Butterbeer cork across the table. "I don't want to talk to you!" Snape sneered again.

"Really? Because I wanted to talk to you." Sirius barely looked up.

"About what?" He demanded, his voice still icy.

"You know what."

"Go away."

Severus stepped into the room and came over to him. "You still want this…" Snape leaned down and pressed his lips to Sirius' bringing a moan and a shudder from the animagus. Sirius responded, as if on impulse, sliding his tongue in Severus' mouth, for a moment, forgetting that he had once vowed to hate this man.

Sirius surrendered to the feelings that had lain dormant in him for years. His need… His lust…

"Severus…"

"Yes?"

"I missed you…"

"I know…"

At some point they left the kitchen and went upstairs to the bedroom, Sirius closing the door behind them, as they sprawled out on the bed, all enmity for the time being, forgotten.

Sirius cast all of his past differences aside, and for the while allowed himself to remember, allowed himself to feel nothing but love and a deep, long suppressed passion for the man above him. Allowing himself the sweet release he had, for years longed for.

Severus broke down all his defences as quickly as Sirius had put them up, knowing exactly where all his weaknesses were, and slowly, and sensually exploiting them.

For the moment, there was no war, no fear, and no pain. There was no dividing wall in the name of separate houses, or different ideals. For a while, there was no hate, no painful memories reminding him that there were some people he could trust, and some he couldn't. That this was one he couldn't… For the moment, he forgot that he'd been hurt…

Sirius slipped his hands inside Severus' robes, groaning as he came in sudden contact with Severus' warm skin, and remembering that night in the forest when he'd first been able to touch him, to show him how he really felt… It was a while latter, when Sirius finally collapsed back on the bad, tired, and sated, and for now, oblivious to the hurt he had suffered.

It was the next morning when Sirius awoke, to find the bed empty next to him, and again, just as he had the first time, Sirius wept. Shed tears of grief and pain, and loss. He knew it would always be like this, he would always be used, and hurt, and he would build up his defences again, like he had before, and he would hate him. He would hate him with a passion. But still, he would never help feeling the sharp sting of rejection. Would always feel like Severus was twisting a knife inside of him. Severus was killing him slowly, from the inside out. Just as he always had done.

Snape was always going to be like this to him: Like Poison.