I used to hate foot fungus, but now it's growing on me.
Foot Fungus Affection
Explanation
Explain Bear
Alright, listen up, you chucklehead. This joke is about foot fungus. The dude first says he hated it. Then he says it's "growing on him." That means he likes it now 'cause it's on him... like he is a moldy, gross foot. LOL. You probably have foot fungus!