Without taking the marriage's history into account, I think it is not fair to decide on this incident to ruin the marriage. Most of you are pushing her to terminate her marriage, while she mentioned that she caught him before talking to anyone, and she still sees him a great person and they both love each others. I think a more reasonable response would be to let her talk to her husband, and try to figure out why he was thinking hookup in the first place. If she discovered that he is a sex addict, and he has cheated on her without her knowing, then it is another story, and she has the right to think otherwise, even though, even cheating doesn't necessarily mean marriage termination automatically. Mistakes happen.