Brother blackmails sister to fuck

In this porn, blackmails her brother's brother. He caught his sister masturbating and threatened to tell everyone everything. The girl nothing left, how to suck him. Then brother decides to fuck his sister. They have sex while there are no parents. Then the guy could not stand it and poured the cum into her mouth during blowjob. The girl spits out the sperm and swears - why did he fill her mouth with sperm.