Relationship Issue :(, Please Help Me!!!!!?

She might be telling the truth. I would joke with her about cheating with this other guy. Just keep the jokes going. DO NOT act worried and paranoid, as that is a clear breach of trust- meaning you don't trust her. She's new in your life, so inside, you may not trust her, and with this other dude around, it makes sense not to trust her. But never show your weakness like that, it doesn't serve you. Make this HER weakness. You confidently move through your life, and if she wants more of your attention, then she'll have to be more forthcoming. This technique will make her very driven to be a good girlfriend to you. If, on the other hand, you are constantly worrying and wondering out loud what she's really thinking, she will basically start to ignore you and these insecurities which may or may not be well founded. If she sees you constantly worried about cheating with this other guy, she knows you don't know and could maybe make out with this guy and still have you to come back to. She could just smile and deny it, and you'll keep worrying either way. IF, you are calm cool and collected, and any indiscretion or childish shennanigans she pulls are looked at as HER WEAKNESS, then she will have nothing but disdain for this other guy.