What should I do? Can I trust her when we leave for college? Or should I just leave her?

[Chad]

I'm 18, male, and my girlfriend is 17. We have been dating for 4 months, and I noticed everytime we get in fights it because of other guys, for example, behind my back she lied to me about her first time and she told the guy she had her first time with to keep it between them and not tell anyone, and she was snap chatting other guys, then we deleted if after she denied doing it, then one of my guy friend saw her on a dating app and she denied it, then on twitter she told admitted to this guy he had a nice body, and she doesn't even know the guy never met him and she told him that yeah if I didn't have a boyfriend maybe I would give you a chance but I do, and we were dating there months at the time the twitter incident happen. And she also checks out guys head to toe in front of me and she will star at them when I'm there as if I'm not. It just always seems like guys are the problem and the fact she said those things to a guy she didn't know crossed the line for me and I should of left

[Erin]

This is tricky to parse out...

Some of the details above make you sound posessive and controlling and hyper-sensitive.
Some of the details above raise red flags about her behaviors.

On the first one, about her 'first time'... she gets a pass. If she lied to you about being a virgin or something, that might be a big deal. But she is not obligated to disclose her 'first time'. Maybe she feels shame or embarrassment... it doesn't matter... it's her memory and her experience, and she's not obligated to offer it up to you.

As far as snap-chatting, I really don't know. It depends on who the guys are and the nature of the snap-chats. The fact that she deleted/denied it it is weird though.

The being on a dating site is a red flag, especially if her account is active.

The Twitter thing sounds like you being possessive. It is acceptable, and a reality of life, to be able to acknowledge that other people are attractive. She didn't say to this stranger 'I'll leave my boyfriend for you". She said, essentially, "I have a boyfriend, so therefore do not expect any sort of relationship with me." This seems reasonable.

The staring at other guys could go either way.... if she's really staring, its inappropriate and a red flag. But if you're just hyper-sentistive, and every time she glances at someone you think it's a big 'thing', then that's lame.

In truth though, long distance relationships are hard, and transitioning to college life is a big deal. If you guys alreayd have all these trust issues and red flags, college will NOT make that any easier. You might be better off apart.