There's been a long standing agreement between you and your roommate that he can free-use your GF whenever he wants. You owe him, and he wants to fuck her hot pussy whenever he feels like. He promised it was a 'no share' arrangement, but one of his friends has a video game he wants, and the only want to get it is to share your GF with his friends.
Your GF is not into the idea. She reluctant and wants you to call the whole thing off. But an agreement is an agreement, and besides, it's only blowjobs, how bad can sucking the roommates friends be?
They're rude and handsy - grabbing her and making degrading comments, she sucks them, swallowing the cum loads, until one of them says he wants to fuck her. She doesn't want to, she's reluctant but gives in eventually. As long as he doesn't cum inside her, she doesn't want to get pregnant. You watch the whole time...