How did I get here?

So for clarification I am not a cuckold. This started with a fantasy I had of watching my wife have a one time threesome with 2 men and I would watch. Once I revealed this and talked her into it (which went easier than it seems it should have) the issue became who and how, we tried to make a compromise and stumbled by inviting in a friend(fail) and eventually it became she would find someone on her own and we would do a threesome- but I would be part of it. That happened 10 months ago and was great however it was not a one time thing. We have been doing so for ever since. It morphed from inviting him to join us to solo visits with him, weekends away, travel etc. Now we have two parallel relationships for her, one with me and one with him and at times they coincide and we have a MFM. I don’t hate it but it is certainly not what I had fantasized about and presented to my wife. I don’t really want to try to squash it as she is like a school girl with the whole thing but I do feel like I hit a slippery slope.