New to ENM: What Boundaries Did You Set?

My partner and I have been together for around 10 years, and over the last while we’ve started exploring non-monogamy together. It’s actually brought us closer in a lot of ways. We’ve been able to talk much more openly about our wants, fantasies and boundaries, and I feel like we’ve rediscovered a spark that we’d lost a little bit.

My partner has now developed feelings for another guy, and we’re currently figuring out what that could look like. She’s interested in a V-style relationship where she could have a relationship with both of us, whereas he’s not entirely sure that’s something he wants. They’re currently exploring a friends-with-benefits situation while they figure things out.

I’m surprisingly okay with a lot of it, but I’m also discovering that some things hit me much harder than I expected. For example, the idea of them sleeping in the same bed and waking up together makes me uncomfortable because that’s something I see as quite intimate and something I’d like to remain “ours.”

I’ve also struggled with jealousy, anxiety and the fear of losing my partner, even though I know she loves me and our relationship is strong. I’m trying to take responsibility for working through those feelings rather than expecting her to “fix” them — I want to understand myself better and learn how to handle them.

So I’m really interested in hearing from people who’ve been through this themselves:
● What boundaries did you start with?
● Did you have any boundaries you thought you’d have but later changed?
● What things surprised you by being difficult?
● How did you deal with jealousy or the fear of being replaced?
● Did you keep certain things (like sleeping together, dates, traditions etc.) as “ours”?
● And what do you wish you’d known when you first started?

I’m genuinely just hoping to hear people’s experiences and learn from people who’ve already been through the messy “figuring it out” stage.