Assuming that my past behavior was an outward extension of my true authentic self, and my core beliefs . . . why would I want to become the diametric opposite of that, just to re-attract a spouse who is having an affair on me??
Now, if the behavior is something I genuinely believe is NOT a healthy one for me, or DOESN'T reflect my true authentic self? Then yeah, I would want to work on that, but I would do it to become a better person, both on my own and in my future relationship, whether that's with my wayward spouse (if they decide to knock it off and come back to the marriage), or with someone else.
But I don't believe in changing who I am, IF I feel good about who I am. Not for anyone.