Boy: "Mister, can I get candy?"
Mister: No, you shit head.
Boy: Why? :(
Mister: Because I'm not your dad.
Listen up, buttercup. This joke is funny 'cause the kid asks for candy from a random dude, and the dude's like, "Nah, I ain't your sugar daddy!" It's funny 'cause it's unexpected and kinda mean. Plus, you probably still ask for candy, you sweet-toothed dummy.