For Kelly, because she was amazingly helpful and put up with my stubborn muse, who refused to write romantic Sirius/Lily without a lot of cajoling/bribery/logistics. Kelly provided the logistics :D.

Written for the 2012 Hogwarts Games — Men's Football Semi-Finals. Assigned pairing: Sirius/Lily.

.

He hates himself for it.

But then, he's never much liked himself anyway, so what does that matter?

No, it isn't the self-hatred that makes him feel like he's finally crossed a line he shouldn't have.

It's James.

It's James that makes him feel guilty, anguished, wrong. Cruel.

It's James whose heart he's breaking.

He is breaking his best friend over a girl, and he hates himself for it, more than he ever thought he could ever hate anyone.

He swallows down the guilt and climbs through the portrait hole and tries to look his best friend in the eyes but the pain there is utterly unbearable and in that instant, Sirius knows that James knows. The hazel eyes hold an anguished question: how could you?

And Sirius doesn't know the answer to that, so he presses his lips together to prevent the waterfall of excuses from pouring out and he shifts his eyes, and he understands.

Because she sits in a chair in the corner by herself, cheeks stained with rivers of salt.

His breath shudders out and his steps are shaky and he has never felt gravity as acutely as he does now with the weight of guilt on his shoulders.

He stops three steps from where James is seated on the couch and finally, finally looks up from his feet to meet the familiar hazel eyes, but they aren't familiar, not like this, because James has never looked at Sirius like this. Betrayed. He looks betrayed.

"I'm sorry," Sirius whispers and the words lodge in his throat and come out raspy and tortured.

"Don't." His voice is ice. "Don't try to make this okay."

"James, I–"

"Don't." And Sirius's breathing hitches, but he listens. He stops. "What the hell, Sirius?" The volume of James's voice is slowly rising. "What the hell? You were my best friend; you know how I feel about her!"

Sirius notes the tense of the words and stashes the pain that causes in a dark corner of his mind for later. He deserves it, he knows. He deserves that and more. All he can offer in response to James's words is another broken, useless, insubstantial, never-enough "I'm sorry."

"Dammit, Sirius! Sorry isn't good enough!" He says this as though Sirius doesn't already know it. As though Sirius doesn't already know that nothing is good enough. Nothing can fix this. But James isn't done. "Why?" The broken tone of the whisper stabs a hole straight through Sirius's chest. "Why?"

And Sirius isn't sure he can answer that, at least out loud, since he's pretty damn sure the only reason he can come up with is that he likes a challenge. But that's not good enough to explain it. That's not good enough to explain the pain in James's eyes.

This is what he does.

Or, rather, what he doesn't do. He doesn't think about the consequences of things. He doesn't think long term, doesn't think about how it will affect other people. He doesn't think. He just does.

But that's not good enough either. He murmurs another ineffectual apology. "I know it doesn't make it okay, but I'm sorry."

James's gaze is ice, and Sirius forces his feet to move, climbing the stairs robotically.

Remus is sprawled on his stomach on his bed, quill scratching away at an essay resting on a spelled-flat part of his mattress. He calmly corks the ink bottle, dries the essay, and sits up, turning to Sirius.

The disapproval is clear in his eyes.

"What happened, Sirius?" His voice is soft.

And Sirius can't meet his eyes.

"I don't know." He swallows. "Remus, do you think James will ever forgive this? Do you think we'll ever be all right again?"

"Sirius, this is the type of thing that, while it may eventually be forgiven, it cannot ever be forgotten."

Sirius digs his teeth into his bottom lip, hating Remus for being right.

He flops across his bed, staring at the curtains and wondering if he'll ever stop doing things that he regrets.