A willy that only comes out at night. A willy that doesn't often have sex during the day.
Morning time:
"Oh Chris, hop on!"
"Ahhh nah babe I'm playing on gta!"
"Oh you're such a moon-willy!"
3👍 1👎
A Willy Moon is when someone flashes their ass at you and their dick flops out between their legs at the same time
"Dave became enraged when his Grandad gave him a willy moon"