Its not a homeless Sims Household. My Sim is trying to Marry Jules MacDuff, who is part of a starting household in a fresh neighborhood. The MacDuff Family includes Flint, Joanie (who is pregnant at the start), Joe, Jules, and Faith, as well as Lora and Felicity MacDuff who appear to be twins resulting from Joanie's Pregnancy. The additional Sims are Helen Hall, who originally lived in the Goth house of Ghosts, and Waylon Wolff, who starts out in the Wolff Family home.
The thing is, the merge households screen from marriage is not cancellable.
I can either, A: bring either Helen Hall or Waylon Wolff into my home, and immediately move them out into their starting home or another random family, or B: close the game and go back to a save from a few minutes before the marriage ceremony. I hope I don't have to restart though, I had no way of knowing this could happen, it seems to be breaking the game code's rules for sure.
I'll wait for a reply before going any further.
Thanks!