My two cents:

Not all men are like this. Some men are. Some women are too. Example: my dad has only ever been with my mother and has eyes for no one else, and it’s so obvious that his friends tease him about it but he doesn’t care what they think. My fiancé on the other hand has wandering eyes like crazy but that’s who he is/how he has internalized his masculinity, so I accept it.

My fiancé and I have talked at length about our particular s3kual fantasies and he has explicitly told me that if the opportunity ever presented itself for a 3-some, he would be in favour of it. Thankfully, so am I. Both myself and my fiancé have gone to strip clubs over the course of our relationship and have been honest about our experiences. The key is that we are open and communicative and laying the truth down on the table before we tie the knot and start a life together. I’m actually surprised that you never talked about this stuff to your husband until now!

Personally I think you guys need to keep going with couples counselling; this is a big can of worms that has been opened. Forgiveness is one thing but forgetting is impossible. It’s likely that your relationship will need to change and adapt from this point forward, and certain values and incompatibilities will have to be addressed.