When Nancy was 9-years-old, she dressed up as a pregnant woman, and I dressed up as a little girl. First, I have to say that she was average size for a 9-year-old, not extra tall or anything. Do you know that several people asked what she was?!!! She had a huge, obviously pregnant looking belly!
LOL! That's an awesome costume! In that spirit, how about a plumber? Wear the typical dark blue uniform with the "gut" showing! Carry a toolbox and a monkey wrench! The visible butt-crack is up to the costume-wearer but it would add to the effect!