While changing Thalia, I ask Sophia to help me out:
Me: Sophia, ask Mama for the butt cream, please. (Oh, no. I just said butt cream. I hope she doesn't make a big deal out of it and get me in trouble...)
Sophia: Haha! "Butt cream!"
(On her way to Mama, she begins to loudly chant an impromptu "butt cream" song...)
Laura: Tell Daddy it's called "bottom cream" or "diaper cream"!
Sophia: Daddy! Mama said you're not supposed to call it butt cream!...
(I know, I know... sigh)