He slowed down as Severus came, soaking in the sight of the other boy as he came over his hand and Sirius's tummy. He groaned, and this time. He did'nt lick his hand clean. He simply lowered his head and got at the source of the problem. He started sucking at senstive cock. Cleaning it with his touche as he gently sucked it, learning from every girl he'd ever fucked.

It was getting less about lust for Sirius. More about connection. About someone the wanted he would't admit he wanted from Snape.