The issue is how the gf feels about me as well as how she treats me. Any woman I deal with should want to spend as much time with me as possible. So, it should not matter if her friend is a guy or woman.

Besides, a woman who cheats will do so with any man that is not me, whether it be with a friend or someone they met off the street, at a function, through friends, at work, etc.

A woman who would rather hang out with friends or feels the need to constantly be with friends over spending time with me is probably someone who is not into me and may want to keep her options open.

In all, a woman who is in her 30s and beyond should be a lil more settled in her life and not have the need to be hanging out with a bunch of people all the time. Hanging out with friends are cool, but if she has male friends, then the polite thing to do is invite me with her when hanging out with them. No solo dolo engagements with male friends and expect pace and harmony with me,