By 
Sometimes I hear of women who deeply regret cheating on the man they love. Not only do they know that this was a big mistake, but they fear that because of this mistake, he will never feel comfortable marrying them.
You might hear a comment like, “Last fall, I went abroad for a semester. I was hesitant to leave my boyfriend, but this was a once-in-a-lifetime opportunity and he encouraged me to go, so I did.” We have been together for three and a half years. I love him very much. I am very close to his mother and sisters. I anticipated that we would get married once we both graduated with our master’s degrees. Unfortunately, I did something very stupid. I was abroad, i started flirting with one of my classmates. i stayed with this guy’s family while i was there. and even though we didn’t sleep together, we kissed and definitely had a relationship. i never intended to leave my boyfriend for this other guy .And I always knew our relationship would end once I got back to school. I was so caught up in the other culture. I felt so free there. I almost didn’t even feel like myself. The other guy texted me the other day Just a message from e friendly text. But my boyfriend saw it and casually asked who the other guy was. It wasn’t even an accusation. But I started to sob. And it all spilled out. My boyfriend was devastated and told me that he was going to ask me to marry him on my birthday, which is only a couple of months away. But he said that now I have ruined everything. As if this infidelity wasn’t bad enough, he was finally going to get what he had been waiting for so long: a proposal. And now I feel like I’ll never get it. Even on the off chance that he could forgive me, which I doubt, I don’t think he could marry someone with that much lack of integrity. Also, if his mother knew this, I’m sure she would break all contact with me and demand that her son do the same. My heart is broken. I don’t know what’s wrong with me, but I know that I love my boyfriend and that if he gave me the chance, he would make a good wife. Is there any way I’ll ever change my mind?”
Well, I can’t predict what anyone might do. It is understandable that he is hurt and hesitant. If the roles were reversed, you could understand how devastated you would feel and how it might make you feel insecure in the future. Because that’s one of the biggest challenges you face: restoring trust. People who have been deceived tend to believe that it could happen again. And that’s why they’re always a little suspicious, even if they really love the other person and want to believe that they won’t cheat again.
So that’s going to be your challenge: to prove to him, probably over time, that you’ll never cheat again. You could try pointing out that he never cheated on her in all the years he’s been dating. I could try to explain to him what the circumstances and the once-in-a-lifetime experience were, but I doubt he would fully understand. The thing is, couples get over cheating. And people who cheat once sometimes never cheat again. To make him believe that this is the case, you must be open to what he needs from you to make him feel safe. This could include not dating again for long periods of time, at least for a while. It also likely means that, for a long time, he will be mistrustful of you until enough time has passed for him to believe in you again.
But this does not mean that it never will. Some people choose to take a risk and trust. And this is especially true if you have proven yourself trustworthy after the dust has settled a bit. Understand that you will have to be sincere and sincere in everything. You never want to give him a reason to distrust you.
As far as his mother is concerned, there may be a chance that he doesn’t want to tell her. Honestly, it’s nobody’s business but yours. If he does something to tell you, then you will need to win back his trust the same way you will win back his: by conducting yourself with integrity and showing him that you can, and you will be a loving and loyal girlfriend who will improve his life.
Once you’ve gradually restored trust and shown him that you’re the kind of woman any man would want to care about, then you can worry about commitment, but I wouldn’t focus on committing until then.