Cheating boyfriend

I really need help in this time of my life. I received anonymous emails saying my boyfriend was having an affair behind my back. I checked it up and found out it was true. The affair is with a woman that has asked him to have a relationship and apparently he said no, however, she told him due to my busy job I couldn't be around that much and she was just interested in his body. Fact is, the secret relationship they keep is really taking place. It all seems she wakes up at around 5.30am and goes his house. Then, she leaves from there to work. This is really difficult for me and I don't know what to do. She knows of my existence but neverthless she acts this way. Well, I know it takes two to tango. What to do? I'm completely lost. Sometime ago I found out, her girlfriend still texts, emails and calls as crazy and from time to time they meet - and it all seems they sleep together. Help, I'm losing my sanity.

A correction in my previous post. When I say "Sometime ago I found out, her girlfriend still texts...", I meant her ex-girlfriend.

Well, if your boyfriend did say no, he obviously didn't say it loud enough, because the affair is happening. You being busy is no excuse for him to cheat because you two can find some time to be together, I'm sure. It might not be the ideal situation, but it is what it is. It's not like you have control over when you have to work, and if you did, you would most likely choose to spend more time with him than you are now. It does not matter what the other woman wanted him for or what she thinks about you, he agreed at some point that an affair was okay to have. So, you need to let him know that this isn't ok. You could break up with him or give him an ultimatum, it depends on how you want to handle this. If you break up with him, ask him before you do why he cheated, why he thought being with another woman would help work things out, and what would he do if you had cheated instead of him. At least you can leave him knowing these answers. If you decide to give him an ultimatum, tell him it is either you or the other woman, and he has a certain amount of time to break things off with the other woman or you are breaking up with him.

You're more than right, Tiles. If he really said no, it wasn't loud enough because she didn't have any problems of going to his house very early in the morning and to call him at any moment. I also found out, when he is on night shifts, she calls him at 1 or 2 am, sometimes at 5,30 am when she wakes up. Tuesday night we were together and I talked to him about it, and I just got partial confessions. There was even a moment during our conversation I went to the balcony for a while, and I heard the door shut behind me. It was him leaving. He went back though. He said he had already finished with her, but also admitted some events were very recent. Of course, I can't believe a word. I am breaking up with him, because probably an ultimatum won't work: they can get sneakier and I don't want anyone attached to me if that same person prefers being with someone else instead. He is begging me to accept him back but my trust is now ruined. I also have the information she is not the type of woman to give up and it seems he doesn't know how to say no loud and clear. I don't want to make part of a triangle and the other woman can have him entirely now. I don't care if he says it's me that he loves, because how can I be sure of that? I prefer living with this sadness of leaving him, even if hurts too much. This is a game I can't win when two persons decide to follow this path. Wednesday I avoided the subject because it was my birthday (though ruined and him trying to do all romantic things). Thursday I tried to speak again with him about this subject and the answer I got was "I feel ashamed about myself and I don't have to listen to it again". With such an answer, what can I do? Nothing. I'm going to dedicate my life to something else to keep my mind as busy as possible. Fact is, even if he tells everything's over with her, how can I be sure? And what to do when I have evidence about something she told him about me (when she was informed I found out about them via anonymous emails)? He told her I was freaking at him and she said "she just needs a good shag and she'll be fine". This is completely out of order and I don't admit it, thus the reason I'm leaving him. Thanks for your answer and help.