Oh, he was more than just good at it. He was amazing. Reaching down to curl his hand in Remus' hair, Sirius let out a gasp. No one had ever done this to him before. Yes, Sirius had snogged a lot of birds in his time but they had only snogged. As hard as it may be to believe, Sirius Black was a virgin and him and Remus were taking leaps and bounds towards changing that apparently.
Fighting back the urge to thrust forward into his mouth, Sirius took deep, gasping breaths, moaning out Remus' name at intervals and biting on his lower lip to control himself. He couldn't be loud, couldn't wake his cousin, but holy hell was this amazing. "Ahh, fuck Remus. Mmm -- m-more. R-Remus, m-more" he gasped out.