Only My Mom: "Crabs"
Mom: "I was listening to Jeff Gaffigan talk about seafood and how crabs are named after a disease. I was confused, so I texted Krutika (my sister) and asked her 'what is crabs?' and she said 'it's a street term for pubic lice' so I thought 'Ew! How dirty. Only beggars can have that disease."