I am willing to let a detailed, skilled Male play the role of mother in this idea.
A Mother and her Son are on a road trip, going to visit her Sister for the weekend. Its an overnight trip and a mixup at the motel forces Mother and Son to share a twin-bed. The sexually-aggressive mother can't help but feel her sons large erection pressing against her and decides to help him take care of it. Its been a while since her husband has pleasured her and, well, her son's cock is a lot bigger.
-This is the start to a Mother/Son affair. The son will be quiet and shy at first, but gradually become more aggressive too. They share a room at the Aunts house and sneak around with each other, fooling around discreetly in front of others as their lust for each other takes over.
-Once back home, it continues. Scenes could involve the son coming into her room at night, feeling her up and having her give him a BJ even while his father sleeps beside her. Things like that.
Message me if interested.