Alright, here's the scoop. I've been in a relationship with what I consider a really cool woman for the last 3 months. We hit it off really well and I'm enjoying myself a lot. Here's the problem. She's still really good friends with her ex, which normally wouldn't really be an issue for me except for these circumstances. Apparently they've been friends for a long time and "tried out" a relationship which (according to her) lasted about 3 months and she realized that she really had no romantic interest in him. He's still close with her group of friends and we end up seeing him a lot in social groups. Again, not a problem normally. But here's the problem.... I think he still has feelings for her. First off, they only broke it off (again, from what she's told me) about a week before I met her. While he lives a fair distance from her apartment, he'll sometimes stop by to hang out both with her and her neighbors. Granted, I'm usually there also but it's still weird to me. I've showed up before when he was there already and that sketched me out a bit. I'm not talking about being in her apartment, but when a neighbor had people over to BBQ or hang out. Apparently they have somewhat regular conversations by text or by phone, which she doesn't try to hide. Either way, I'm not the jealous type but something seems off here to me.

Another addition to the problem is my ex-girlfriend and I had a very similar problem. When we first met, she was friends with her ex, although they had been apart longer. Just like this guy, we got along and he seemed to be an alright guy but he ended up causing us grief throughout almost our entire, almost four year relationship. I see a lot of similarities in the two guys. Actually, I'd call them glaring signs but I'm worried I'm just being paranoid because of past BS that I had to deal with. He seems a bit nervous around me and almost seems too anxious to try to be friendly with me. He's almost too nice. Anyway, I'll skip a lot of the details. I don't want to be an ass and make her give up a genuinely close friend but I don't want to feel like I'm being a sucker here by letting something slide that I shouldn't. I have no time for someone that may be pursuing MY girlfriend, whether he has any chance with her or not.

Any advice would be appreciated.