First, Fergie of the Black-Eyed Pees lets loose while singing onstage. It's important to free yourself within your music, you know, and really...let go.
Then, Jenny McCarthy has a little too much fun during a radio prank. Here's a pre-pee picture, so you can identify her face.
At least Jenny has the excuse of having recently had a baby. Maybe there's a medical reason she lets go when she laughs a little too hard. What's Fergie's explanation? Prudently, she has said nothing publicly.