Why do people never kick their own balls?
Because they might lose one!
Listen up, buttercup. This is a knee-slapper about kicking yer own "balls." See, it's funny 'cause "balls" can mean yer actual family jewels *or* a single ball used in sports. The joke is you wouldn't wanna kick your own junk off, would ya? I'd be surprised if you knew that.
Lol
g