I don't know how you flirt, and I can't even tell the most glaringly obvious signs of when someone is flirting with me. However, once, I did get insanely jealous when two guys approached my ex-friend and started talking with her, while I was there. I just wanted to punch them in the face or something, tell them to back off. I was in love with this ex-friend, though, and love clouds judgement, as the guys were about twice my size and would kick my chubby arse in 10 seconds.
I'm sorry if I derail the thread, but yeah... I loved her very much, and now she's essentially broken up with me just because I happen to be trans. She's lovely and smart and I just wanted a chance to make her happy, to spend time with her, to run my hand through her soft hair, to hold her and make sure everything would be okay. I still miss her.