My wife and I are at the end of a triad relationship where the wife "thought" she had a DADT agreement. As their relationship started to skid she offered him to stop seeing us which turned into a "you've been fucking them?!?! since when is seeing them fucking them??!"
A complete emotional mess for everyone. Which translated into us not being able to see each other at all anymore.
A and I have chosen to go Mono with each other per her request though she always puts that "for now" addendum on everything as the escape clause.