Request is simple, would it be possible to have a mod that lets you marry multiple characters? I dunno how the room thing would work, but maybe it could just keep the first one you go with? Hell, I'd settle for them coming to your house and being there with your other spouse. (this may be because I heard Shane might be a bachelor in the future and I want him AND Harvey.)
From what I've read by just browsing this forum, the answer is currently know. Want Harvey and Shane? Easy to do! You've got multiple save files. Try different challenges while playing the game.