Sirius' should'nt have thought that back arch was hot. But he did. Severus was confusing on that level. Everything he shouldn't on the boy, he thought was hot and sexy. And the fact it was Snape? Pretty much ruled out everything. Nothing should be sexy. But here he was his thumb teasing the other boys hole. Two days ago he would have never admitted to wanting to do this with any boy. Let alone Snape.

He raised his wand and quickly muttered a spell.

" oleum "

He smirked as he cool liquid coated Snape's hole, Sirius was suddenly very glad he'd checked out the naughty spells in the restricted area. He placed a surprisingly gentle kiss at the base of Snape's spine as his middle finger started to press into the other boy.