Boyfriend Reminds Me of My Girlfriend

Alright, listen up, you cotton-headed ninny muggins! You're so dumb that you probably think a 'relationship' is just a ship between two relatives. This joke is about role reversal and ironic comparison. The narrator's boyfriend is jealous and accuses her of cheating, so she hits him with a sick burn by saying he reminds her of her girlfriend. It's funny 'cause it implies the boyfriend is acting like a jealous girlfriend, turning the tables on his accusation. Get it now, Einstein?