Every now and then my wife forbids me to kill a character. A good example is Bathocles in my short story The Pasion Contract where, even as I was writing it, she told (ordered) me, "Bathocles has to live."
The moment Helen wants to protect someone, it's a signal for me to maim, mutilate or destroy the guy, because it's the characters you care about that mean something when they suffer. I've never actually diverted the plot to run over a character Helen likes, but then I've never really needed to since if you're stuck in one of my stories then you're already in great danger.
This has led to some conversations that would be considered unusual in most households, such as an intense and prolonged negotiation over how many toes I was allowed to cut off one nice but care-worn fellow, Helen arguing for none and me for all but one per foot. The decision turned on how many toes were required for the character to hobble about for the rest of his life. Some of the negotiation was carried out in a public eatery and I wish to apologise to the people sitting next to us.
This reached the stage where I said, "You do realise, don't you, these people don't actually exist?" She did, but apparently it doesn't matter, which is good news for me because it means the characters are working, but probably bad news for the characters. The moral would appear to be, try hard to stay out of my stories.