"We said time isn't right here. When I got here it was just before my sixteenth birthday, and I haven't aged since."

Sirius manages this much. But as he pauses to take a breath, he isn't sure what to do with his hands. Isn't sure if what he's going to say is going to help. But he'll regret not saying it later, he thinks.

"I think...I think Peter didn't believe we were really friends. I wasn't very...I bullied him." Which Remus must know, especially a Remus who's an actual adult. "I didn't work with You-Know-Who. But."

Sirius trails off, drops his gaze.

"I'm sorry. It hasn't happened yet, for me, but. I still. I'm sorry."

What else can he say?