Blubber shirt
The oversized T-shirt that a obese person wears at a waterpark or swimming to cover their immense flab. When wet, it adheres to the blubber, defeating the purpose of wearing the shirt.
Her: Did you see the size of the cannonball that guy did?
Him: What guy?
Her: That guy, the one in the blubber shirt.
Him: What guy?
Her: That guy, the one in the blubber shirt.