re: Interested to hear your story if you found out your partner cheats with multiple people

If this is all true, you are likely dealing with someone with a personality disorder. It’s a type of crazy where the person doesn’t have normal interpersonal boundaries or sense of shame. Dealing with them will make you go crazy, and it sounds like it already has. You have to go no contact with her and her kids. Insist your family go no contact with her. People like this like to stay connected to everyone they ever knew and she will always worm her way into your life somehow. Work on yourself and respect yourself more in the future.