Fat Mum and the Monster Truck

Alright, listen up, buttercup. The joke is all about your mom being super huge. Like, so big that when she plops her caboose into a monster truck (you know, those giant cars with the massive tires), the suspension system just gives up and turns it into a lowrider. It's funny because it's an exaggeration, and it's also insulting... just like you.