Your gf has been struggling with her grades lately. Luckily for her she's getting one of those grades raised. Unfortunately for you, you have to see her professor's huge piece of meat resting on her innocent face.
My friend found this pic of his bimbo cumslut mom on her phone, but is too much of a pussy to post her. Comment what you think of her and if you want more, so that he changes his mind.
Surely you would let this go on even if you became a couple. He was even grateous enough to let you come and watch the next time he and his friends has their way with your "innocent" crush.