I agree with ntl, you are very lucky that he opened up and told you about this before he took action. Everyone else on this board was kept in the dark by their spouse, so that shows you how common the lying and cheating is.
Your relationship is pretty good is he will be open and honest with you. You do need to show him he is special to you. You should thank him when he does something nice. And you can take care to look good and make the dinners he likes. I acted like we were dating. When my H came home for dinner and we were on tenderhooks, I dressed sexy, offered him his favorite beer or wine, then had an appetizer ready. nothing fancy, just like chips and dip; hummus and pita chips, things like that to nosh on while I cooked dinner. It got him to hang around the kitchen and talk instead of going to the bedroom and watching tv while I cooked.
You will not be able to control him on the trip. You will have to trust him. He is right; messing with that woman would be a very bad idea professionally.
It's important for people to remember that being married, or even being happily married, is not a vaccine against lust. We are humans and we still feel a spark around some people. It takes self-control to not act on lustful feelings. But having them does not mean there is anything wrong with the marriage. It just means that there is more than one person out there who can make your pulse quicken. It actually has no meaning about the 2 people. The fact that he gets excited by her doesn't mean that she gets excited by him, or that anything about the two of them is "meant to be." People let that feeling go to their heads and act on it. And then later they realize that that impulsive act ruined their otherwise very good lives.
