I mean that's really bad to hear that he got cheated. That's so bad about the relationships when don't actually know the meaning about being true to someone. Things go really worst for the person who's suffering, the one who did it will just move on well, some will criticize them but they do have thay idgaf attitude and that's basically temporary. The person who's left behind has all the burden and the majority of problem first the divorce and all that alimony issues.
I hope your friend tries to cope up with this situation, it's difficult but still...