Each of us are different. We all have different needs. One of the hardest things to do is step outside and look into your own sitch.
Look at your own sitch like all three people (You, W and OM) are complete strangers to you. Each one has their own story. Understand each persons story. This is detachment. What needs are being met by OM? Are you capable of meeting these needs? Why is W attracted to OM? Why has she lost attraction for you? This is the growth that you need to go through. It is the hardest yet most rewarding thing you will do.
"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