I assume people flirt for the same reasons married women wear low-cut tops or men do their hair and clothes just so: to get some attention and a bit of thrill. Both of those reasons don't necessarily mean anything sneaky. It could be anything from just being extra-friendly and liking to show off to actually trolling for another person. You never know.

A lot of people, especially women, grow up with the idea that their self-worth is significantly tied to male attention, and they mourn the loss of said attention as they get older. Men do too, but women are encouraged to make a lifetime out of hair care, makeup, clothing, personal maintenance, etc. -- nearly all of it tied to validation from not just men but also other women.

I think when people might be feeling a bit low or lonely it's a charge to be noticed by someone else. Sometimes that notice and the opportunities it might present go too far, of course. I think a *lot* of this has to do with growing older and wanting to feel that someone else still finds you attractive. For some folks, though, that's just the way they are: they flirt with nearly everyone. I don't really get it either but am not in other people's heads. Joking and a little teasing, yes. Flirting -- well, I think people would just laugh at me!