It is more likely than not.
dont give him a chance to put your heart tgether again until he has proven he wont break it again. dont get your heart broken again.
I think your question lacks information. For example, does your boyfriend and his ex have kids or any other reason for talking? Also, are you saying he has cheated on you with her?
* One word - guilt. * It is true that you do feel guilty. You should take the chance and be honest with your boyfriend and tell him why you cheated and if you mean it tell him it won't happen again. Let him know how guilty you feel and be sure you aren't going to pull this stunt off on him again. Rule of thumb ... 'respect gets respect!' How would you like to be cheated on? There ya go!
how do you know if your boyfriend has cheated
Sounds like you need a better boyfriend.
Next Boyfriend....
Every person is difference, it is a 50/50 chance.
Say that you will give them 1 more chance if it happens again it's over
tell her that her boyfriend cheated on her. she needs to know.
not to be rude but if he cheated on you i would not take him back. find some one else there are plenty of fish in the sea. no man should cheat on there girl. because he cheated on you if you do get him back he's going to do it again and again behind your back and im not trying to be rude just trying to keep you from getting hurt again
If you still fancy him, give him one chance, but make it clear that if he gets caught again, he is out.
All you can do is tell him that you are sincerely sorry, and will never do it again. The rest is up to him to decide if he can trust you again. Give him that right because he deserves it after what you did.