A little strange though, he figured, considering all that Moony had told him about this Sirius after he'd thought he was gone. It wasn't as if it'd been anything too private, but -- well, they all had strange windows into each other's lives, being that they were each other, and Sirius felt as if he had another, since this Sirius was dating the Remus from his world.
"Moony told me a bit about you," Sirius offered, because, as strange as it all was, Sirius didn't want to dance around it. And he figured that if he didn't put out there, this other Sirius would.