My (M31) GF (F28) wants an open relationship, how to make this work?

I (M31) have been with my girlfriend (F28) for just over three years.

We recently got our first mortgage, and finally got through the process of legally adopting her child from a previous relationship (bio father is out the scene). Our home life i feel is really solid, got a great emotional connection, amazing family life, our child is thriving, we communicate well, and our relationship is stable. I’m really proud and happy of what we’ve got together.

But this week, she told me she’d want to talk about exploring a more open relationship. She said monogamy has always felt a little unnatural and restrictive to her and that she’s been suppressing part of who she is. She wants to be able to explore with others whilst still keeping our emotional connection and family life strong. She assured me that she loves me, wants to be with me, and isn’t looking for a replacement but just the ability to physically explore with others. So she brought up us being a non-monogamous couple and opening the relationship, which is something I don’t fully understand how that works.

I don’t have much knowledge or any experience with non-monogamy, so I’m struggling to figure out what that would look like in a healthy way. I don’t want to agree to something just to make her happy if it’s going to end up hurting me or us as a couple and I also don’t want to lose my own sense of what has been good and what works well in our relationship.

For those who have been in similar situations or have an opinion :

- Does this kind of relationship actually work better than monogamy in the long run?

- How do you establish boundaries and rules to keep the relationship strong?

- What are some common mistakes couples make when transitioning into an open relationship ? 

- How do I figure out if this is something I can genuinely enjoy, rather than just tolerate?

- Any advice on handling jealousy and insecurity in a healthy way?

Obviously I love my girlfriend will always want the best for her, but I also don’t want to agree to something that doesn’t work or creates issues. Now she’s brought it up, it will be a conversation that we will need to continue, she’s already mentioned how it’s a good thing for couples as it creates more honesty & communication, further deepens our emotional connection, allows for a more diverse bedroom life and could be fulfilling for both of us as I on occasion travel with work. But I’d prefer to bring back up the conversation knowing more.

Any guidance from those with experiences of navigating non-monogamous relationships would be really appreciated.

Thanks in advance