From what I can gather in the game, it's only family members at the moment. Although I'm willing to bet Fiona caves and joins in.
In all probability, MC would like to marry all his ladies, but let's be honest, it's going to chaotic as it is with (cue rapid mental counting) seven family members and perhaps Fiona all sharing a Big Day. And since Killer7 wants to wrap up this phase of their story, there's only so much you can get done before all sense of believability goes out of the window.
I sort of get the feeling that, now phase 1 is nearing completion - and, in Killer7's mind, IS complete - there's now a yearning to get it over and done with so he, and we, can see What Happens Next. I'm kinda with Killer7 on this, but then again, the writing has been that good, I've been eagerly anticipating every new part.
By the way, Killer7, I don't know if you are likely to read this, but there is literally only one thing that I feel a need to see before the end; everyone cuddling in a big pile. No sex, just one big happy family, perhaps in front of a log fire.