I've always been a huge flirt. I think it started when I grew boobs at age 12. I know I'm doing it, but it doesn't mean anything to me. I'd flirt with the bearded lady in a freak-show. I almost can't even help it though, I just do it and then later think "I really wish I hadn't been like that, or said those things."
I have gotten a lot better at stopping myself though, because I am married and I do love my husband a lot. Flirting may not mean anything to me, but I'm sure it means something to him, so I just don't do it anymore.