I have always been fascinated with the idea of someone getting busy with their mom. Your story sounds pretty good, but I think these ideas could make it a lot better:
The mom catches him having sex with a cherry pie (to avoid lawsuit). Then she eats it.
Every time the son starts getting near his mom’s dingum, he says “Home, sweet home” because he was born from there.
Since we are already pushing the boundaries, we can have someone make love to a dog. We could even have someone make love to a dead person. It is not my bag, but that is hot these days.
queef poison gas – self explanatory
an old lady falls down the stairs
guy gets hit in jimmy with a bowling ball. Someone else yells out “spare!”
We show people how to make a bomb.
The guy learns how to hypnotize women into letting him watch them do their dirty business.
A guy starts a recycling service for tampoms, so all the women give him their used tampoms, but he doesn’t really have a recycling service. (jackpot!)
the mom tells him that if he doesn’t finish all his vegetables, he can’t have any dessert. Then she points at her poonanny.
Mom says things are getting serious. She introduces him to her parents. Note: he has never met them before because he is interracial and they don’t tolerate that
Mom tells him to clean his room, but he is like, “we have the same room! We are doing the horizontal boogie together!”
They go to a priest. He tells them that it is not a sin as long as they wear an onion around their neck (or Funyuns – product placement)
What if the mom had that disease where people eat through her butt? We could explore it in a lot of ways. Does she have teeth in there? Does she have to brush them? Does she use the same brush for those teeth as regular teeth? What brand of brush is best for that?
At Thanksgiving, they get caught doing the deed. Everyone is mad at them, but they think it is because the turkey is dry!
I have a lot of great ideas here and tons more. I have some connections, too. My sister used to smoke Dennis Haskins’s (Mr. Belding) doodle. I propose a 60/40 split. (60 for me, obviously)