No words. Take action. Just don't show up for MC.

Later, IF she asks then you say (in person):

H:"W, We both know you are still in contact with OM. I decided there is no point in going to MC."

"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