I wonder if your wife gets to -5 hearts she will cheat on you???? Can you implement that?

Betrayal...? Seems more realistic...if this mod is aiming on how to deal with a boyfriend/girlfriend or husband/wife relationship, they shouldn't have to rely on a mod for it, but just to show there are consequences, this could be interesting...

Feature: Player dies instantly via fire upon trying to marry another villager? :P

Looks to me like you cannot in fact procreate with someone unless you're married to them -- if you can't do that, then the NPCs shouldn't be able to.

I'd say it would be reasonable that if your spouse goes below the gold-hearts range, their messages stop being "loving", and if they get down to, say 3 red hearts, they might divorce you (with some given chance each game day).

At most we'll probably make it where they just end the marriage the next time you speak to them - provided their hearts are low enough.