*During a press conference over the weekend for the upcoming film “What to Expect when You’re Expecting,” the real life mothers on the panel were bombarded with lots of personal questions about their pregnancies.

Co-star Elizabeth Banks and the book’s author Heidi Murkoff gave some insightful details about their experiences, but as expected, the press just had a field day with Jennifer Lopez, grilling the “American Idol” judge on every aspect of her pregnancy and delivery of twins Max and Emme.

With a movie to sell, J.Lo was surprisingly candid – laughing about the swelling of her nose and feet, and how she forgot the lyrics to her own song in concert – which she blamed on “baby brain.” She also revealed a post-partum incident in which she broke down to then-husband Marc Anthony believing the twins would love the nurse more than her.

Jennifer Lopez in "What to Expect When You're Expecting"

But it was co-star Cameron Diaz who practically brought the press conference to a standstill when she blurted out unsolicited, “Does anyone in here know why boobies sag?”

After a smattering of confused reporters answered “gravity,” the actress (rumored to be dating Sean “Diddy” Combs) launched into a rather lengthy anecdote about her experience with Masai women in Africa that you wouldn’t believe unless you heard it yourself.

Listen below.

“What to Expect When You’re Expecting” opens nationwide on May 18. Watch the trailer below.