Fidelia hit the nail on the head with their post so nothing more to add on that front.
Just a question though, if your husband felt the same way towards another 3 or 4 women, would you feel comfortable inviting them all into your family or is there a limit in your mind as to where that would be? Just with the way you write, like these relationships can just spontaneously happen, if it spontaneously happens 3 or 4 more times without any breakups is that ok?
I sort of feel that without any "Structure" to relationships you're just opening yourself up to problems that you'll only face "as they happen" and they often happen through choice. For instance I meet some great women, but because I already have 2 live-in girlfriends and we've discussed our limits I just don't entertain in my head that I will go down that path with them. I feel if I was your husband I'd just keep bringing back women and be like "got another great one I connect with, is that ok and can you sort out her room sweetie?".