When a fupa (alternatively spelled f00p4) gets so big that it develops a nail bed and grows the f00p4n4yl. The f00p4n4yl is often problematic, as it tends to get caught on clothing and can cause rips. Only Lucien Pellat-Finet and Hurvah are known to be f00p4n4yl-proof. Some cultures use f00p4n4yl clippings as a form of currency.
Fatass: I'd be so rich in one of those cultures that uses f00p4n4yls as currency.
Skinny Friend: Yeah, you are quite a fat fuck.