Kid: Dad, where do you work?
Dad: I.C.U.P.
Kid: HAHAHAH!!!! See you pee.
Kid: Dad, where do you work?
Dad: I.C.U.P.
Kid: HAHAHAH!!!! See you pee.
Listen up, buttercup. This here joke relies on a simple trick. The dad says "I.C.U.P", which sounds like "I see you pee." The kid thinks it's hilarious 'cause it's kinda naughty. You probably still pee your pants so it must be real funny to you.