Ok so many people are going to shoot me down here and im ready for it. The fitst thing to ask yourself is this, is he really sorry o sorry he got caught? Im guessing by your post he didnt tell you, you found out. In which case was he displaying the signs or did he confide in someone else that he was doing it? Did he try to deny it when confronted because its all relevant.
Yes if you want to in time you may move past it but im telling you now you never forget. I matry my fiance in 8 days time and when our youngest was 1 he cheated on me. Had it not been for the kids i would of walked away. In many ways i am glad i didnt because we are stronger than ever now, but there was a good couple years where we were very rocky after.
For me it worked and he often tells me how lucky he is that i stayed with him because he realises how much he has to loose. It ultimatly comes down to if you can ever trust him again. Did the communication stop before you found out or because you found out. If its the latter thats not a good signof things to come. If he stopped the communication before you knew its btter but still not good but if she cut communication then i would setiously think about ending it