When you stay in wet clothing (usually swimming trunks) for to long, you're butt begins to itch.
Thus causing you to scratch it profusely, often ending in you looking like a monkey.
Dude, I went swimming and never dried myself off, now I have the worst case of monkey butt ever!
The Urban Dictionary Mug
One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.
Buy the mug