Would you rather save your spouse or your nagging Flat-Earth mother-in-law from drowning in a local lake?
That's a trick question, if you save your mother in law your spouse will died, therefore the woman you saved is no longer your mother in law In other words the true question is Would you save your spouse or some woman that used to be your mother in law( but in all intents and purposes an acquaintance and nothing more)?
!!!∑(°Д°ノ)ノ are you sure that's ok? I mean is that right? does all relationship with in-laws end with the spouse's death?
not related legally but... still kinda relate in the eyes of society... ok I have the perfect solution to this @Kadmos1, prepare to have your cake and eat it too!!! what you can do is save your mother-in law. then you have to marry her! in effect you have saved both your spouse AND your mother in law, what's more, as a bonus, your new wife's mother is another mother in law! all together you get to have a spouse and 2 mother in laws! Massive profit! You are welcome!