Getting the tears to stop was a mighty task but Sirius likewise mostly managed it, if only because everything was still a bit of a shock and his brain wasn't catching up fast enough to keep his emotions any kind of steady.
He'd cry more later, no doubt -- and he'd seal himself off from anyone else while he did so. Sometimes even the most social of people needed that moment or week alone in order to figure out how to cope.
But that was later. For now -- well. Sirius figured he could muster something of a brave face, because it was clear his best friend had gone through so much more than just a spell in the dirt and some tears. Remus had been all alone and with no one else, no friends to help. And here he was, apologizing for it. It was ridiculous, really. Pure rubbish. And so, so Remus.
So. Sirius could at least help with that. "Course you did," he said after a little sniff, to clear out his nose and throat a little. "You'd be silly not to. Have you seen these dimples?" He went for a smile (and sure, it was forced, but he tried) and poked at his cheek with slightly muddy fingers.