Could you tell me if what I'm doing is wrong?

My ex and I broke a few months ago. It was a long distance relationship and when I went to Texas to visit her, I got to meet her friends and hung out with them (we’re all girls, by the way). Anyway, after our break-up, her one friend (who she rarely sees) kept in contact with me. She’s a hell of a lot of fun and we have talked about going a trip together in the future (not for a year, though). She’s just a cool chick and she’s more opt to be the one to contact me. There’s no interest on my part whatsoever. We never talk about my ex.

Well, my ex caught wind of the fact that her friend and I are talking and she is bothered by it (this sounds like high school, doesn’t it? I’m too old for this shit). Her and I (ex) decided that we both need time away from each other (no contact) and that we’re going to move on, but, maybe, down the road we’ll be able to have a friendship. In all honesty, I really don’t want to have anything to do with my ex right now. I’m feeling so much better about things and am moving on.

Do you think that it’s wrong that her friend and I are talking (it’s all innocent and nothing really)? Why do you think that she is bothered (worried)?