Many women do more than that when they're alone with themselves. But the contrived rules do not allow them to relax with a partner. It is not without reason they say, that a smart woman has it in her head, a fool has it in her mouth. I even know men who categorically reject such liberties.
The slutty mother loves to get a hard cock in the ass. And the son is happy to try. After the preliminary caresses, he attached himself to her anal hole like a miner to the slaughterhouse. Cum dripped right down to the floor from the ass of the satisfied lady.