Just from the nature of your fears, may I assume it is not you who has a new romantic interest, it's your (male?) partner.
I know you want to obscure the story to keep things more anonymous, but this doesn't help the quality of feedback you get.
You can keep anonymous by using a unique nickname (hope you're not "plantlady" anywhere else), not sharing your living area, profession and details of your conversations and day-to-day... the big picture tends to repeat itself in many stories, it's unlikely you would be recognized by anyone other than your partner(s) and close friends who experience the same timeline on events firsthand.
Thank you so much for sharing all of that. It is very helpful.
In our situation, we have been living a poly-like lifestyle of sorts for probably the last 10 years of our 25 year relationship/marriage. We just never had the words for it, before becoming connected to friends in the poly community.
We've accepted that there are some incompatibilities of sort, or simply things that interest one of us but don't interest the other, and we have no problems with having those needs fulfilled outside of our relationship. We have never limited intimate relationships and that would appear to most as being close friendships, but to us they are deep soul filling connections. Deep level of emotional intimacy and physical affection but not sexual affection. None of these relationships have ever been romantic, though we deeply love them.
That is the shift is that one of us is feeling romantic entanglement with someone, and that relationship, although it is not a brand new relationship, the newness of the romantic side of it is shining a spotlight on the areas of our primary relationship that are lacking.
There is no conversation or thoughts around having multiple romantic partners as being a way to fix or fill the gaps in our relationship. Honestly, stumbling into this romantic territory was not something that was intentional. But now that we are there, there is this tension where, in my mind, continuing into this space that we found ourselves in could be detrimental to our desires to rebuild things that we have lost in our relationship along the way.
All discussions surrounding broadening our boundaries for other relationships have been put on hold. But I fear we've wandered into a territory that is going to make repairing our relationship more difficult.
Let me repeat to make sure I understand.
Sounds like you both place high value on intimate relationships and are comfortable with the other having these.
Yet somehow, you avoided falling in love with your close friends. (Was this an actual agreement, or just never discussed?)
Also, sex hasn't been on the table (I assume this was an actual agreement? has your partner cheated on it?).
Now your partner has fallen in love and they want to take it sexual. The romantic part was unintentional, but you recognize very well it cannot be undone. So the two of you are having a crisis.
You put your foot down and said "no" to his wish to introduce sex to the other relationships --- at least until other issues have been discussed.
---------
I think you are right this is going to make relationship repairs more difficult, but since this is not a hypothetical scenario - a new love interest is already on the table - here you are to deal with the difficulty.
You don't say this, but you are likely terrified of the change. That's normal.
In a strictly monogamous marriage, unlike poly, the only ethical solution would be to cut ties with the new partner and let the crush fade.
Maybe you think that is what your partner should do - and this would indeed make repairing the relationship easier. But it won't work if they feels like they'd be ripping out their own heart by doing that... (been there).
So they don't want to cut ties and they're asking you to transition to full poly instead.
How are you feeling about possibly being poly? Is it a "no, I really don't want that, romantic and sexual exclusivity is important to me", or is it a "I might actually like it if our relationship was more healthy"?
If it's the later, it may be possible to take the hard route of working on repairing the cracks while opening up. This will require time, patience and commitment of all three people involved. For the two of you, it means scheduling time for both the necessary discussions (or couples therapy) and dates. Maybe make it one on one - if they spend an evening doing fun stuff, you also get an evening date just the two of you, no kids, no obligations? You might actually get dates more often this way
For the new person it means their relationship can't progress as fast as they'd like. It's important to be upfront with them about what they can expect.
Hold tight, this is going to be a rollercoaster
More than ever, be kind to yourself and do your basic self-care. Best of luck.
