(I only felt bad for doing it in front of him and not for actually swearing. Swearing is an alternative to killing people, and keeps me out of jail so it's the lesser of two evils.)
So, feeling remorseful, (not really) I apologized to him.
"I'm sorry Little Man. Mommy wouldn't swear so much if people just stopped acting like assholes."
This made him laugh. "You said 'ass,'" he said. That word always makes him laugh, though I'm not sure why. Maybe because ass-->fart/poop. And of course boys and men love bathroom humor.
Now, before your eyes bug out and you go write me a hate comment please know that I do not make it a habit to swear