Help and advice appreciated
-New to forums, please let me know if I've posted in the wrong place-
My wife and I are in an open marriage. We have spent hours talking it over for the past few years and established our boundaries explicitly. One boundary we established and both agreed to was that in the event that either of us fell in love with another person we would stop the relationship with the other person. Neither of us are willing to accept the other having serious romantic relationships outside of each other. We have had semi-serious tri relationships together, which we agreed was ok. Currently she has become seriously involved with a woman that is a long time friend of mine. It was originally just an exploration of sex with a woman, as the relationship I mentioned before greatly lacked the sexual element for us both. I am not sure how to adjust to a sudden desire on her part for our previous boundary agreement to be revised greatly. I have been through 7 weeks of hellish NRE and the original agreement has been ignored and now she wants to date her and continue the relationship. I'm trying to be caring and fair to them both in lieu of the feelings that have developed, but I feel slightly un-cared for because we had all of our boundaries spelled out before anything ever happened. If I could be so bold as to ask for advice/techniques/mantras really anything to help me adjust in a way that is healthy for myself and of course them?