Your mama is so fat when Santa went down the chimney he said, "Ho, ho, ho, holy shit, you're fatter than me, bitch!"
Santa's Fat Joke
Explanation
Explain Bear
Listen up, buttercup. This "your mama" joke is all about exaggerating how fat someone's mom is. The punchline is Santa, Mr. Jolly, got shooketh and even cussed because your mama is so obese. It's funny 'cause it's rude and unexpected, kind of like your last Tinder date.