Originally Posted by SchrodingersCat
Threatening to dump you every time she doesn't get her way is nothing but an adult temper tantrum.
It sounds like you both have a lot of emotional triggers that make it difficult to have a balanced, calm conversation when difficult issues arise.
Can you and S find some way to create a new way of interacting that leads to a more harmonious relationship? Less ultimatums and more negotiations? The way you describe it sounds more like an ongoing drama