Hope, It's amazing how similar our situations are. The only difference being is that my H owns the company, well, so do I. I think he likes to pretend that I don't, but it will certainly hit him between the eyes if it ever comes down to divorce when he has either sell the business or buy me out.
As far as you exposing the affair at work, I totally understand where you are coming from. It would not only effect his life, but that of yours and your DD also.
I will tell you that many people know about H's affair including our two DDs 17 & 20. It didn't seem to phase him. He even had the audacity to invite DDs with him to take his mother out for a family b-day gathering. He failed to mention that the OW was going also. The girls were not happy with him at all. They were very uncomfortable with the situation. The other humiliating part was that youngest DD met them there with her friend because they had other things to do first. Can you imagine how embarassing it was to show up at the restaurant with your friend and your married dad be there with his secretary/ow. That was not the only shock the girls got that day, DD and friend got to see him in his new "rug". He had never worn one before! Talk about a MLC! LOL!!!
So, I guess what I'm trying to say is if the situation would effect your daily life, then do what you think is best. Honestly, I'm not sure they would be fired and then you would have to put up with the gossiping. This way at least the OW isn't able to flaunt it in your face because it isn't common knowledge at work.
Life's challenges are not supposed to paralyze you, they're supposed to help you discover who you are. -- Bernice Johnson Reagon