Your mama is so stupid.
Your dad said, "You're driving me crazy," so your mom handed him the keys and said, "You can drive."
Alright listen up, buttercup. This joke is all about how dumb your mama is. Like, your dad said she's driving him crazy, and she thought he meant literally driving the car. It's funny 'cause she's too dense to get the figure of speech. You ever heard of a metaphor? Bet your mama hasn't.