I met this girl a month ago and talk and text all the time. We get along very well and are very comfortable together. We have been shockingly honest about everything. She just got out of a bad relationship a few months ago and we have been taking it slow because she was confused about her feelings. Well today she met her ex to work on subletting their place and she slept with him. Now I don't know what to do. She did tell me about it a few hours later when we talked but I don't know if I can get past this.

She still has feelings for her ex. That is what happened. Leave her alone.

You're setting yourself up for a real heartbreak if you continue with her after this. Homegirl is correct... she probably still has feelings for him.

In this case she didn't do anything wrong because she told you right from the get go how she was confused about her feelings towards her ex. You should have taken this as an indication the first time on what the outcome would be. For now, the best thing you can do for yourself is leave her alone and not hold out any expectations or hope she will choose you over him. If it were really that simple, she would not have gone back to her ex. Anyway, the better off you'll be if you're not with someone who feels the same way about you.

I'm sorry this is the case and I hope things get better for you. Best of luck!

She has sent me a few texts trying to explain. She says she still has feeling for him despite everything he did and is trying to move on (I didn't know its only been 2 months since break up and they were pretty serious though he left her). I don't doubt she has feelings for me. But I don't know if I can trust her or look past this. This is the first night in a month that we haven't talked, normally we talk for at least three hours. And not all chit chatty things, serious stuff that most people only talk about to few if ever other people. She keeps texting and apologizing, but I'm not a second place pushover. She may regret what happened but it still happened and she didn't stop it.

You definitely don't want to be the fallback guy. You deserve someone who wants to make you number one. If she is flirting with the idea of going out with you while being conflicted about her ex, she has a lot of issues to resolve. The best thing for her would be to be by herself until she figures out what she wants. She probably feels a deeper emotional connection with you but it's loving the idea of what's familiar that keeps her stuck on her ex. In any case, she should realize that talking to you for hours and texting frequently sends you mixed messages. If she wants to be fair to you and herself, she should limit the amount of contact she has with you or she should simply leave her ex if she feels she also has feelings for you. She is really doing everyone a disservice.

You really don't have much invested. Move on...

She didn't have to meet her ex unless it was to sign documents in a public place.
'Work on subletting their apartment' was walking right into trouble and she knew it. She could have kept all such 'work' done from afar.
On the other hand, if you like her enough to forgive her, there's no law against it. Just cool your jets for a while so you get out your resentment alone. Let her know that you need that time and that you don't know how long it will take.
Plus it serves a double purpose: it gives you time to see if she's fickle and runs back to him.

She just got out of a bad relationship a few months ago and we have been taking it slow because she was confused about her feelings

That's all the warning you needed to realize you had to protect your heart, and maybe not give it to a stranger, or have high expectations for a great, perfect future. No she didn't cheat because you were going slow enjoying getting to know each other and enjoying it, and I do understand the disappointment, but don't miss the honesty of it either.

How you handle it going forward is the main thing because the dilemma is how to cope with YOUR feelings and not the actions of a confused female fresh from a bad break up. It was your mistake to think you were building something big in the first place given the warning signs.

Reassess your expectations and see the part you played in this, and be as honest as she was and if you cannot cope with the reality you are in, remove yourself completely from the situation until you can.

Sorry guy, but you set yourself up as a rebound to a hurting, confused, and very vulnerable female looking for an escape from the bad relationship. Had you recognized it and kept a safe emotional distance with a new text/phone buddy/friend/acquaintance, you would be disappointed, but not surprised by her actions.

That's the problem the shock and surprise she ruined what YOU had in mind. It was probably closure for her. Even going slow doesn't prepare us for the actions of one that is still carrying baggage from the past, and barely into the healing process.

You really should have know she needed a friend, and not romance. Now you know that for sure.