If your wife really did cheats on you and you are willing to carry on the marriage. Either you are so madly in love with her that you cannot see the errors of your way to stick on or you are someone who did not accomplish much in career and is fearful that you be heading down the path of loneliness in the event of a divorce.
Your wife sleeping next to you does not means she will sleep with you forever. A spouse that cheats mean that he or she is not happy with the current marriage. Such spouse are always very selfish people that only care about their own needs. They have no love for their own spouse else they would not have cheated.
Your situation is exactly the same as my friend previously, he continue to be super nice to the wife and keep assuring himself one day the wife will regrets her actions and start to appreciate the marriage.
He even caught the wife cheating and confronts the wife. But he forgave the wife and hopes she would change. Unfortunately she did not change and carry on cheating knowing he would still be super nice to her and forgives her. Except that this time round she is much more careful in covering her tracks.
End up the wife left him for another man that is willing to marry her and that can meet her needs.
As for him due to the tremendous amount of emotional abuse, he is now a broken man marked with scars forever.
If your wife really did cheats, she is not leaving you now not because she wants to stay in the marriage. She is not leaving you coz the man have not given her any commitment. If the man ever decided to marry you. It is bye bye forever for you....
If you are still willing to carry on loving her.... instead of praying that she will change....you should pray that the guy won't propose to her...that is the only reason she is staying on in the marriage......And who knows as long as no one propose to her. She will stays married to you. With time passing by, eventually her beauty will be gone and so will the guys. She will then have no choice but to stick with you forever.
Btw saying all this on the assumption that she really did cheat on you. If she did not and all this are just a pigmentation of your imagination...Then just stay happy in your marriage.