Stepmother fucks stepson after training... to maintain her skills

Melissa works out every day to stay in perfect shape, but unfortunately, her husband doesn't appreciate it. However, her stepson does, and he often peeks in on his sexy stepmom as she works out. Soon, she realizes that she arouses desire in the young man and wants to see how far he will go. Asking him to massage her legs after training, she makes him massage her tits and pussy too, which immediately turns into incest.