How would you react if your classmate told you “your mom is hot as fuck”?

Hi, I’m a Chinese student and my mom and I recently moved to Canada, so I’m still getting used to the culture here.
My mom came to pick me up from school, and after seeing her, one of my classmates suddenly told me, “Your mom is hot as fuck.”
I honestly didn’t know how to react. My English isn’t perfect, so at first I wasn’t even sure how seriously I should take it.
Is this just the kind of joke friends make with each other here? How would you respond if one of your classmates said this about your mom?
“20”