Trying to get my gf into the lifestyle, guidance appreciated!!

Context: I'm 28, my girlfriend is 23. We've been together 5 years and I'm the only guy she's been with sexually. We're in the UK.

I first brought up the idea of involving another guy in our sex life about 6 months ago with talk of a threesome. Not going to lie, I was hoping that this would lead to me being cucked, especially if we found a third who was hung and had sexual prowess (both of which I lack). She was into the idea, especially during dirty talk, and agreed to proceed, albeit nervously as she's an anxious person generally. We got to the point of taking photos to make a profile on a swingers site but, being able to tell how anxious she was about it (and partly due to my own nerves), I called it off.

We hadn't spoken about it again until the last week or so. We've been far kinkier lately, and I've been talking a lot about enjoying watching her being sexual and slutty. After a separate conversation about her potentially meeting a female domme, I brought up the prospect of thinking about involving a guy again and potentially going to a swingers club to test the waters. Her reaction this time was far more open and eager - mentioning us at least thinking of bringing in a guy and trying the swingers club put a big smile on her face, and she seems far less anxious about discussing it this time. Talk has been vague so far but we haven't even mentioned it being a threesome, just generally the idea of bringing in another man - so outright cucking could be on the table. She told me she hasn't been actively thinking about it since I first brought it up but that maybe the idea has settled in her mind more, and she likes the taboo aspect of it. Crazy to me that the idea seems to have worked it's way into her mind and become less nerve-wracking to her despite me not even talking about it for months.

I dont want to push too hard and fast now and make her anxious about it again, nor do I want to put her in a situation she's uncomfortable with just because she thinks I want it. Does it sound like we're close to making it happen? How should I proceed with this?

Guidance from more experienced cucks or bulls would be greatly appreciated!