My girlfriend Cynthia has been unfaithful to me several times. Recently, I invited my coworker to my home when Cynthia was there. I knew he had a strong attraction to her. There was a moment when I wanted to talk to her, but she completely ignored me while smiling at him. I insisted, but she continued to ignore me while smiling at him until I raised my voice, and Cynthia responded to me in a very bad manner: WHAT? My coworker told me: Stay calm, just pretend like nothing is happening here. And weeks later, she told me when we were in bed: Your coworker came to my store today. I asked her what he wanted, and she told me: He came to have a drink with me, and it's not the first time he's come. He's been checking me out for a while. I became very jealous and angry and asked her why she hadn't told me anything before, and she became defensive. I told her that he wanted something with her, and she said that he had invited her to go out for drinks one night, just the two of them. I told her that I hoped she had told him that she couldn't go because she had a boyfriend, and she told me that she had said she would look for a day when she could. I got very angry because I noticed that she was attracted to him, and I reminded her of how she had humiliated me in front of him at my home when I invited him over. She told me that it was very ugly, but she didn't know what was wrong with her, and that when she was with him, she couldn't control herself. I asked her if she still loved me, and she said yes, and that I shouldn't worry. And then she told me: Maybe I should meet up with him. I asked her why, and she said: to explain things to him. To explain what? Something he already knows. Given her history of infidelity, what do you think is going on between them? If they've been meeting up for a while and she hasn't told me anything, don't you think they've already had sex?