Lost my filter

OMG, why do I say these things?! Coming out of my mouth before I could stop it... "Some of these parents think that the sun rises and sets out of their kid's........ (butt)!" (Said to a very professional and kind professor re: a student in his class) My parents always used very colorful sayings that apparently I have picked up, and they reverberate before I ever have a chance to stop them. I'm so embarrassed!