That's terrible though, and there's no way you could have predicted this. I'm sorry for your loss. But for relationships it's common sense knowing that they will most likely end judging by the statistics and what we see in everyday life
I can't trust women no matter what, I'm too redpilled/blackpilled for that to happen. To me, women ARE enemies waiting to strike. The moment you show weakness, or the moment a better man shows up in her life it's basically over for you. It's a mog or get mogged world out there, there's no place for emotions or trust. It's no wonder men keep getting screwed over in relationships and marriages, they don't understand how women work
Though talking about it all the time like your ex did would be annoying as f*** to deal with. I'd shut up myself if I were in a relationship, but I'd resign myself to the fact that someday it's gonna be over and that I can never allow myself to love or trust her, never let my guard down or show any kind of weakness whatsoever. For me she would be just a body to f*** that I have zero emotional attachment to