<human>: Can you succinctly summarize the text in 1-3 sentences?

So I have a girlfriend over the summer going into college. We are going to colleges 2 hours apart, so we decide to change our relationship to being a "break". Our break means that we can be open-minded going into college, but we're still together. However, if one of us hooks up with someone or wants to date someone else, we tell the other person so we know we can end things between us immediately. 

So my "girlfriend" or whatever I should call it goes to a dance with a kid, and shes posts pictures all over facebook with him. I accuse her of hooking up with her but she denies it. I visit her a couple weeks later and we start officially dating again.

Fast forward 4 months and while she was visiting me, she was drunk and told me she made out with him. I call her a cheater and a liar and she has been crying non stop. Her reasoning for her not telling me about it is that she thought I would end everything with her and that she would lose me.

However, I always brought the kid up and accused her of it and she fought ME about always bringing it up and I ended up being RIGHT. She has lied about this for 4 months and only told me about it when she was blackout drunk.

So basically, can I trust her ever again? Did she cheat on me? She claims she never wants anyone else and she keeps crying, but I don't know if I should believe her.
<bot>: Girlfriend constantly lied about hooking up with a guy while we were on a "break", she only told me when she was blackout drunk and now I don't know if I can ever trust her again.