"Regulus can set the boundaries. You know me, I'll take what I can get." He smiled weakly, feeling his resolve waver. He didn't want new boundaries with Remus, but he doubted that would actually matter.
There was a lot he could have said, about how Remus was one of the only people on the entire planet he'd ever trusted. How he and James and Peter had taught him to be better, and showed him what it meant to have someone actually care about him. He could tell Remus how much he loved him, and always would. Lily hadn't stopped Sirius from loving James, after all. He could tell him how things with Regulus were complicated, and Sirius didn't know anymore whether he should spill his secrets to his brother or not. But it was all too much, too fast, and Sirius didn't want to face any of that today. Or ever.
So instead he stood, hands jammed into his pockets and shoulders hunched.
"I, Remus, you know you'll always be my friend. My best friend. You and James, you're... Yeah. But, I can't, right now I just... I need a shower. And everyone will be up soon so..." He nodded toward the stairs, a sickly smile still bolted on. He made it almost all the way out before he turned back and hugged Remus from behind, fiercely. Like a goodbye. And in a way it sort of was. Goodbye to who they had been. Who knew what they'd be next. He broke the hug after a moment, then all but ran up to his room, locking the door behind him.