So here's the situation. I've been with this girl for about 9 months now. We live together. About 3 months ago I visited home for two weeks. The first night that I left my girlfriend went out to get drinks with her guy friend (she had a hard time handling me being away for two weeks, I think she just wanted some male attention). Lets call him 'John'. She told me about it when I talked with her on the phone a day or so later. As far as I know this was the only time she hung out with him during the two weeks that I was gone.

A little back story on John. My girlfriend and I both know him through a mutual friend. The only time that my girlfriend and John hung out, prior to me leaving to go home, was for a week long period, prior to us getting together. She was on vacation in the city that he used to live in and they ended up hanging out and becoming friends that week. She claims they never hooked up but he is clearly attracted to her. He's a bit of a alpha male I would say. Hooks up with allot of girls that kind of thing. She says they are good friend's but she has really only hung out with him for 7 days. I think she is oblivious to his intentions and probably a little bit attracted to him.

Back to the story. She has not hung out with him since I've been back home. A couple days ago he texted her asking her what was up. She immediately told me he texted her and didn't try to hide it. The next day he texted her back asking what she was doing that night. I was with her that night and she told me again that he texted her but that 'she didn't want to hang out with him because he only want's to hang out when he has no females in his life' ( I thought this was a weird statement because she claims they are just friends).

My question is what would be TRP was of dealing with this situation. I'm very comfortable in my relationship at the time being and would like to keep it going for a while longer. I don't think that she cheated on me yet with this guy but I think it could happen in the future if she keeps communicating with him and starts hanging out with him. I don't trust that she would be able to be responsible if she felt attraction for someone else. I think it would be silly of me to try to verbally confront her about the situation. I've been just trying to monitor the situation and keep on focusing on bettering myself. I think the only way I can win is to make myself more attractive then the other guy. Any other advice from TRP?

TLDR - Girlfriend of 9 months is friends with an alpha guy who clearly is attracted to her. She says they are just friends. What is TRP way of dealing with this?