Wrists
Now I may be making this up, but I remember a r/s fic where one of the boys thinks something like, "and Sirius/Remus has wrists that he wants to bite" or something. I have not idea what fic this was in and if anyone recognizes it, lemme know. (It's not expected, there is wrist biting in that, but that just reminded me of the aforementioned paraphrase).