Yo Mama So Fat

Alright, listen up, buttercup. This joke is saying yo mama is so obese, even a tragedy like a "bombing and 89 stories" (likely referencing 9/11) couldn't off her. It's funny 'cause it's soooooo dark and exaggerated. But hey, don't worry your pretty little head about it too much. You probably wouldn't get it anyway, what with your limited cranial capacity and all.