Sirius just barely managed not to shout at Remus again and it was mostly the fact that Remus had pulled his wand out that kept him from doing so. His hand went to his own wand out of some instinctual response more than a real concern that Remus was going to hex him. While he did agree that Remus had every right to fling a spell at him, he didn't really want it to happen. Luckily it was just the wall that was in trouble and Sirius watched, a lot of the anger draining out of him, as Remus sunk to the floor.
He wiped a hand across his eyes and even though he logically knew that he had every excuse to cry right now, he still felt some shame over it.
"Hey," he moved to sit on the floor next to Remus, trying to sound comforting, but there was a strained quality to it as he struggled with his own emotions. "We don't know how it works here. Maybe it's like a time-turner, yeah? You'll go back and it'll be right where you left off, no matter how long you're here. It's not finished. When has there ever been anything we couldn't do, huh? We can make it right."
He slung his arm around his mate, letting his hand rest on Remus' shoulder and squeezing there.