Any ideas on what he could have on her to blackmail into this in the first place? It would have to be something potentially shocking enough that she'd let him screw her to keep me from finding out!
There is a picture of her and her man kissing in a sofa some years ago on a party before you met her. She is is in a extremely sexy outfit, and several people you know stand around chaering and smiling. His man and your gf is giving a show
Your gf is a nice girl, and regret the whole story very much. The teen's man is senior to you somehow: your boss? your gf has not been honest to you, and beside the fact that she regret the situation, she is also very worried that the guys watching should tell you. She is going to marry you, and she is affraid that the picutre would japordize this.
The teen has been hot on your gf for years after watching the patry through a window, and taking the pic. he has been mastrubating to the pic ever after. He shows the pic to your gf and tell her he will give it to her if she will do the same with him
She dresses in the same outfit, ask him to sit on the sofa, and they make out. He tell her about all the mastrubating to the pic, and looses his jeans. He take her hand and ask her to do it for him. Only once. After, she will get the pic. She helps him. He promise to bring the pic the day after. He don't. Just his cock. Again
and again. he arrange to have a new pic taken with a spy cam (or maybe a friend of him takes it standing outside the window) before he giver her the first (which of course is only a copy)
After some time, she sart to enjoy the sex, but is more and more scared what will happend if you find out
From here, there should be a lot of oportunities for interesting developments A cuck to my GF - A bull to all other women