It's essential to acknowledge that the narcissist's behavior in their new relationship does not indicate true happiness or change. They didn’t change for you in the relationship, so why would they change for someone else? They are likely repeating the same pattern of idealization and manipulation that you once experienced. The love bombing stage they are currently in is unsustainable, driven by their need for external validation and control. They will stay in this phase with their new supply as long as they need to, but this stage is often short-lived. The narcissist has no incentive to change for their new supply, just like they had no incentive to change for you!

Narcissists put on a show in their new relationship to get a source of validation and to ease their deep insecurity. Appearances are everything to them, and being viewed as being in a happy, successful relationship gives them the admiration and reassurance that they so desperately need. Everything is a competition and a chance for them to prove they are superior, and being in a successful relationship is a win for them, especially after coming out of what they are telling everyone was such an awful one with you (aka smear campaign).

They also want you to gaslight yourself into thinking you were the problem. If they can control your thoughts and emotions even after you’ve separated, they are still controlling you. Perhaps they even think they’ll be able to lure you back into the relationship due to this new version of them you are seeing. But you’re smarter than that.