You need to sit down with this woman and talk to her, and tell her to be totally honest with you, because if she's not, then it is indicating she doesn't want to share herself 100% with you anymore (emotionally). It's obvious that she doesn't want to share herself 100% physically with you right now. After you figure out what's going on in her head, you need to figure out what's going on in your head. Of course you still love her, because to you your relationship was runnin along smoothly. But you know what? She doesn't love you, at least not enough to respect your relationship & not cheat. CHEATING IS LIKE RUBBING YOUR FACE IN THE FACT SHE DOESN'T WANT YOU ANYMORE. Now, I know that she might want you some, and other guys some, but then that's not a relationship, that's friends with benefits.
I'm going with everyone else when I say, she did this ON PURPOSE, it was NOT an accident. Now, if she had been at a party and gotten drunk and you weren't there and she just randomly had sex with someone she didn't know, that would be in some sense an ACCIDENT. However, she got this guy's phone number (sign of straying #1- WTF does she want with some random 'hot' guy's phone number?), she went out with him- twice (why does she want to go out with him?) she LIED to you about what she was doing (BIG RED TRUCK! super-obviousness of subvert schemeing here) AND THEN to top it off you had to drag it out of her (if she really and truly regretted it, she would have come clean to you without prodding.)
Plus, I'm thinking this chick is at least what, 25? You share a computer- HELLO- it seems to me that she wants out of the relationship but didn't have the balls to tell you, so she cheated on you and let you figure it out yourself. Sharing a computer is like, the EASIEST way for your SO to find anything you don't want them to find.
Now, think about this- if the situation were reversed, what do you think you would be feeling? What would your motivations be? Would you have gotten a hot chick's phone number, gone out with her, had sex with her, and lied to your girl about it if it was done on IMPULSE? I mean, IMPULSE is something you do within a space of a few hours, not dragged out over the course of a few days, or weeks.
Could you ever think about anything else but her fucking some other guy if you two stay together and have sex? What would it be like, imagining him doing all the things to her that you do? What if he was better than you, what if his dick was bigger, or more satisfying? What if she's wishing it was him screwing her? You're going to have to deal with all these questions EVERY SINGLE TIME you have sex with her if you stay together. She broke your trust, and if you stay together you're going to be paranoid for the rest of the relationship.
I recommend a clean, swift break. Better than than getting crushed with a steamroller- which is what I forsee if you stay together.
And remember, TFP is always here if you need a shoulder (or shoulders) to cry on!
