He cheated on his girlfriend with me. Why is he ignoring me?

Because he feels ashamed he did that to his girlfriend and he feels even more ashamed that he used you. He hurt you. He feels bad about it.

He is probably trying to figure things out and understand his emotions. The fact that he cheated on someone shows how confused he is. He feels bad about what happened and maybe he hadn't thought it through. Give him some time to acknowledge his wishes and needs. Also allow him to talk to her and explain what happened.

He might have wanted to get some sort of revenge on his girlfriend, so he cheated, but he actually cares about his girlfriend.

Well, to me it seems like he regrets what he has done, and usually men tend to run away from their emotions to avoid making a big deal of everything. What I think, is that he is pulling himself away because he himself doesn't know what to do regarding the situation, maybe he still has feelings for his girlfriend or maybe he is just looking for a way to tell her it's over. Only time can tell. But you should ask yourself .. are you willing to be a choice in someones life ? There are a lot of single men out there, you shouldn't accept to be the other woman. You deserve someone who will love you unconditionally and be yours and only yours.

because he wants his girlfriend now, and decided that she is worth it.

I've been in this situation before except I actually use to be this guy's girlfriend. He started leaving me for other women and got himself new girlfriends and he's cheated on all of them with me and denies it to them. They actually believe him. At those times I wasn't aware that he had a girlfriend or that he was even seeing someone. If I knew I wouldn't have slept with him. He always found some type of way to tell me after the fact that he had a girlfriend. If you actually know that he has a girlfriend why are you sleeping with him? He's putting this other girl before you that's why he's ignoring you. He's not obligated to contact you. He has a girlfriend and it's not you. It's really self explanatory. You're not his girlfriend so he doesn't have to answer you back. Now if he just doesn't want to talk to you I strongly suggest that he just tell you that in place of ignoring you.

Most people when they're in the wrong, they tend to ignore and isolate themselves from situations. Since he cheated on his girlfriend, he knows it's wrong so he wants to distance himself from the entire situation.

This man is a betrayer of trust and has made a mistake in judgement and character. He is probably filled with shame and guilt for his actions, he may even be feeling regret. The action he did was wrong therefore he is coming to terms with what happened between both of you.

I would suggest a change in question as no one is going to be able to answer that question without access to his inner mind. Maybe he is feeling guilty and not wanting to face up to what he has done, maybe he is torn over how to proceed, maybe he had a new computer game delivered and has been totally engrossed and just not thought about it... no one but him could possibly know. This means that if you even try and guess the chances of being right are slim. :) How about we ask this question instead, who do you want to be? Sounds like quite a shift huh? Hear me out. What if you decided who you want to be, how you want to act in situations, how you want to be treated, what your boundaries are... as in 'if this happens, i will do this' etc. I suggest this question as i think all other answers fall out of it easier. So do you want to be someone who presumes to know what is going on without any information? Do you want to be someone who guesses and works with that guess as if it were truth? Do you want to be someone who focuses on what someone else wants rather than the most important, what do you want? What do we know? He cheated on his girlfriend with you and you haven't heard from him recently, maybe you have seen him and he has even blanked you? My question would be, does it matter why? How about the other thing that matters is what you want and what you do and that comes from answering the question who do you want to be? Sometimes we avoid thinking of exactly how things are by trying to guess how things might be different. However if we accept what we know and only what we know then it becomes easier to make decisions. Are you someone who wants clarity and calmly would contact the guy and directly ask him to have a conversation about how things are? Are you someone who if there was no reply, would see that he is not communicating and move on with your life.... making your life the best possible life to be in for you and for all those around you? There will never be just one potential guy in your life, or even 10 or 100 or 1000 potential guys.... there are lots. Your heart has the capacity to love many different people, many different times and be broken and heal too. The pain we feel in the moment becomes the experience we build on in the future. Our challenges make us stronger and teach us about ourselves way more than any easy time would do. Consider changing the question to be less about why he wants to do what he is doing, and more about what you want you to be doing because your only authority in this life will be over you and your actions and impacts. :) Good luck! :)

It's normal to feel guilt after abandoning someone close. Guilt is a very strong emotion, and it affects us all. If this is the case, he could possibly be ignoring you because he feels so much guilt that he has to be loyal to his girlfriend again.