I think the thing that makes people uncomfortable in this kind of scenario is if you don’t stop when they ask you to. Or you just refuse to take no for an answer. But our species would cease existing if nobody ever was made uncomfortable at some point by flirting because everyone’s lines and desires are on a spectrum. You can say the exact same thing the same way to two different folks and one will turn around and slap you for it and the other will get on their knees for you. Humans are weird.