Yo mama so ugly, she got a lifetime ban from KFC for ordering too many burgers.
KFC Ban
Explanation
Explain Bear
Listen up, smarty pants! The joke is that yo mama is so fugly that even KFC, known for serving up questionable "food," had to cut her off. Imagine being so rough that not even a bucket of fried chicken can fix it. Also, you're probably overweight since you like jokes about food so much.
Noobdude16
makes no sense