noodles

to answer the initial question in an obvious way: the only surefire way to find out if she's cheating short of a confession is to find undeniable proof in some form.

finding this proof will require you to either go looking or for it to stumble into your lap. if you go looking, you clearly no longer trust her and risk her breaking up with you, especially if she is not cheating on you.

to make a long story short, this sounds like you're insecure. your girlfriend will have guy friends, period. the majority of my girlfriends have had more guy friends than girl friends, and thats cool with me, even though the majority of my relationships have ended because of cheating (not on my part).

you may want to consider sitting down and talking to her if its a serious problem keeping you awake at night. that would be much more mature than stalking her for proof.

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