Both are living in a fantasy world. Fastest way to pop that bubble is to push them together. Most wait to long.
I don't think "Push them together" is the correct word choice, but I can't edit the post.
They both are only dealing with the "good" parts of a relationships and do not have to deal with the "bad" traits of the other person. The LBS's get to experience that part. When we have enough self respect not to tolerate their bad behavior and set good boundaries, they can either choose to end the affair or move out.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712