Brother blackmails him and goes through his sister's ass

There is nothing worse than being blackmailed by your brother if this is a pretty bastard guy whose feelings don't give a shit. This girl is well fucked, because the brother has something with which he can blackmail her. So he blackmails her and goes through her ass while her parents are sleeping in the next room. He is not content to fuck her, something he has already done several times, but prepares his anus, puts a little oil and nails it all over his ass. The girl suffers and says "shit brother, what are you doing to me", but he doesn't stop for a second until he runs.