Son caught his own dad having extra-marital affair & cheating on his stepmom, so he blackmails him to let him fuck his own stepmom 3 times
For 3rd time, before dad-son could plan anything on how... they trick stepmom to be fucked by her stepson, stepmom revealed that she knew that her stepson has been fucking her and her husband has been cheating on her, so she now demands that this would be permanent.
From now her stepson would become her husband and take care of her, whereas her husband will be her father-in-law & he can continue with his affair.
As a punishment, she made her husband (now father-in-law) watch her getting fucked by her stepson(now her husband) and began a new life with her family
