Yo mama so ugly, when I put her next to a naked mole rat, it said "bluetooth connected."
Bluetooth Mama
Explanation
Explain Bear
Alright, listen up, because this is a tough one for you smooth-brains. The joke is saying your mom is so ugly that even a naked mole rat, which ain't winning any beauty contests itself, thinks she's a device it can connect to via Bluetooth. It's an insult, see? And you probably have Bluetooth earbuds permanently glued to your ears, don't you?