Taboo mom and wife

[oddniceguy]

The idea here is that the man's mom has been working really hard to not just seduce his wife, but to seduce her for a lover she is cheating on his dad with. Slowly, the wife gives in, and before she knows it, she is going on a date with her mother-in-law, and the man she is cheating with. Mom helps cover for her to keep her son in the dark, until after the Lover has fucked her raw. Mom either shows her son the video of his wife begging for another man's baby, or he is in the room as it happens, but either way, his mom tries to entice him to enjoy the show, and their love-making by offering her body. Why now? Well, she can't get pregnant anymore, for one reason or another, and she wants her new relationship to have a child to raise. So in payment for "borrowing" her son's wife, she offers taboo pleasure to her son.

Anyone interested in writing this out?