So, basically he's turning to you not because he's grown up, but simply because he realizes he's physically safer around you when his back is turned...
Not particularly motivating.
You need to look long term here 4luv.
You can't give him a shot because you love him. If you want a LIEF PARTNER you need to know you have a person who will be there when things are crap.
Guess what?
Things got bad with OW and what did he do?
Look at how he HANDLED that situation... She's pursuing like a clumsy newbie divorce buster and he bolted and headed for the door.
Think long and hard on this... he's just playing a safer bet here... what aobut when he's having a MIL or your business takes up a lot of your time, or some attractive woman hits on him?
Think long and hard here... Yes, he's working the reconcilliation plan... working it well, but seriously... He's a wayward guy now... Is your H working on his marriage or hiding from his OW?