It was easy to blame him, to blame Sirius. He was the one with a reputation, which he had done nothing to keep in check. It certainly didn't bother him to let people think they knew more than they did and to judge him for it. And admittedly, he still did have more experience, but Sirius hadn't pushed it. And as much of an initiator as he was, Sirius knew sometimes Remus worried that all Sirius wanted was to get in his pants.
But this attention...the way Remus was moving against him and kissing him, it was not something Sirius could ignore. And by no means did he want to. His lips were finding ways to kiss and bite that delicious skin, with noises to appropriately designate his thoughts on Remus's words. And that last part...Sirius pulled back with a big grin, "And what kind of hello would you like?"