What is the appeal on eating ass?

I (26 F) am single and in the dating scene for a bit, I’ve gone on a few dates with men and 8/10 times I get asked if I’d let them eat my ass I thought it was a joke at first but then it kept happening. Is that like a thing, I’ve never had my ass after our wanted someone to do it 😂 is it normal? Is it actually something people enjoy?