My two cents

Well since my only two readers gave me their opinion, I'll post mine. (I know I have a few more readers, but typically only Summer and Grumpy post from time to time)
On Flirting.
When you're a single person it's great. More power to you. When I was single, the flirting was great for the attention. I can be an attention hog.
However, when you're in a relationship, it's inappropriate. That's not to say you can't notice an attractive member of the opposite sex. (As long as it doesn't involve major the gawking, jaw dropping on the floor, drooling kind of thing)
I think it's a matter of respect for the other person. If you truly love your partner, you wouldn't hurt them in that way. And, yes, for the record, it does hurt. Many people may not admit it or others may have much loftier self-esteems than I do, but honestly if someone openly flirts with another person it's like a slap in the face.
Some men (and women) just don't get it. They think it's harmless. They think "my partner knows how much I love them so they don't have anything to worry about." But let me say that if you're flirting, your partner is probably questioning how much love you have for them.
I really like how Summer put it.
"There is nothing wrong with admiring another attractive human being but, flirting is pursuing. It's the beginning of the chase. "
Let me explain why this bothers me so much. My ex-husband. He constantly needed validation from women. Didn't matter who. He had to have his ego stroked. And his flirting was much more subtle. It was just "being there" for those female friends or doing favors etc. Talking them online. Writing letters to them in prison. (I kid you not!) I had a hard time stroking his ego (or anything else for that matter) because of this. It was a major catch-22. But the flirting, the talking, the being friendly, blah, blah, blah lead from one thing to another. It eventually lead to him getting a bj from a prostitute on a business trip. And yet the idiot in me stayed in the relationship for another year. But you know what the straw was that broke my back? Another new "friend." He met her at an SCA event. They became pals. He'd spend hours emailing her and assure me that she was just a new friend. I could never affirm whether he had an affair with her or if there was anything more to it. I read the emails I could and mostly they were general stuff. I'd been thinking about divorce for a while at that point. And when I found him once again in conversation with her, I made a comment about it. And he blew up. Told me to get over it and be more secure. So I went and got the letter I had written telling him that I agreed divorce was probably the best idea. Up until that point I wasn't sure if I wanted to go through with it or keep trying. But I finally realized that he would never be able to let go of the other women. And I couldn't be happy if he didn't.
So, you're wondering what brought all this up, huh?
No, Marty didn't do any flirting (that I know of) in front of me. But he mentioned something about it. And he does seem to have a different take on it. He mentioned a female friend and said that when they're together sometimes he flirts. He said that he mostly did it to make this other girl jealous that had a crush on him and he wanted nothing to do with her. And there's nothing wrong with that. I'm assuming all of this flirting etc. took place before we became a couple. But I let it be known that in a relationship it wasn't a good idea. He seemed to disagree, but didn't argue the point. I asked him what if the situation was reversed. He said that he wouldn't be jealous. I laughed. Men always say that and they are soooooo wrong. You should have seen him when I was chatting with Patrick online once. (Though he continues to deny any kind of jealousy.)
I may be completely wrong on my feelings on this. But it really doesn't matter. If it hurts someone else (no matter how "innocent"), then it shouldn't be done. Plain and simple.
Do feel free to continue to comment on this.