Ruari, i think a flirtatious man who is married to me is not worth the trouble. Eventually he will cheat on his wife, if not with you then someone else. Flirting leads to something and you don't need that. You have more self worth and esteem otherwise you would not be asking this question. I personally would not remain friends with a married man who flirts. He will always have a roaming eye, and if he does it to his wife, he will do it to you if you get involved with him. Being friends with him can also label you as a homewrecker even if you are not. People love to run their mouths in an office, I know. Best to find a excuse to not be around him anymore. Those are my thoughts. I hope that helps.