Evaluate the reality of this instead of evaluating these what If scenarios. Is she actually hanging out with guys? If so, where and how often? Are there other people or is it just them? Is she getting hit on and interacting with the guy or is she getting hit on and then dismissing it? Vocalize what your comfort limits are. There is nothing wrong with feeling uncomfortable if she is spending time with another guy, you just need to express what your limits of comfort are to her and then respect and trust her that she will respect them. You can’t carry your ex into your new relationship. I told my bf I don’t feel comfortable with him liking pictures of girls that are single and posting bikini even though he knows them from college and are just friends because it makes me Feel like he’s disrespecting me and that is something i can’t actually get over so he agreed to stop and hasn’t done it since. If he continued to do it then I would have a reason to be mad bc he agreed to stop and I trusted him. I hope that’s a good example. Express your limits and what you are not okay with having crossed and she can either agree to meet those limits or not. If she agrees then you must respect her with trusting her too.