Believe nothing he says, and only half of what he does. If he truly is ready to work on things he will make it known over the course of the next few weeks with no doubts.
I find it hard to believe he went from a car ride where he told you a bunch of things he doesn't like about you, to an hour later wanting to work on the marriage. Turnarounds like that are unheard of and I think you are right not to trust it.
Further, the complaint about the "I am amazing" thing. Really? He felt manipulated by that playful little game? It sounds like he has some serious self-esteem issues and I would HIGHLY...HIGHLY recommend you make IC a requirement for him in order for you to agree to work on the marriage. Remember, if he truly wants to work on the marriage he will be willing to do just about anything you ask in order to do so.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018
