1. A person who exhibits wild or violent behavior when exposed to a naked ass.
2. A person who is obsessed with large curvy asses.
“George is a quiet reserved accountant that rarely leaves his apartment outside of work. He also happens to be a rumpomaniac. The last time he attended a dinner party, he accidentally walked into the bathroom where a woman had her bare ass exposed. What happened next can be found somewhere in the Huffington Post.”