I'm married to an addict. Lying is just a part of their make up. There's an expression in A.A., if their lips are moving, they're lying. I've found this expression also serves for MLC spouse and teenagers.
Anyway, I'm not saying you should accept it and I think it's awesome and brave of you to set him free to find his way... But, maybe this is a chance for you to clarify YOUR OWN EXPECTATIONS.
I learned a long time ago to love the core of the person not the surface behavior--mainlu because the surface behavior usually stunk. Throughout our marriage, I've clung to an expression someone once told me..."You knew the job was dangerous when you took it."
If you decide this man is truly who you want in your life, then, you may need to incorporate such a mantra in your own life. It puts the responsibility for your choice to have this person in your life (someone who has let you down before) squarely on your own shoulders.
Not to say he shouldn't earn your trust and be a good guy. But, in my world--with an alcoholic mom and addict husband, lying sorta comes with the territory. Even my mom who has been sober for nearly 40 years in A.A.--well, part of her person, part of what I love about her in fact, is the reality that she embellishes the truth. A LOT.
You could ask her what the weather is and there's every possibility she will lie about it. Not because she is a mean or nasty person, but, for some weird-a$$ reason that even she doesn't really understand... maybe she worries a lot about saying something that will pi$$ people off? and maybe she???? whatever...her issues.
My point is...sometimes loving "dangerous" people means accepting certain qualities about them that may not be politically correct, but the bottom line is...what can we live with and what can not tolerate???
And, what is about us and what is, ultimately, about them??? I'm a strong enough person that I can handle a lie about the weather. I also, apparently, can handle a lie about being faithful...if I CHOOSE to take that dangerous job again, well, that's completely on me and either way--I can't blame him.
"You know, it's times like these when I realize what a superhero I am." Tony Stark/Iron Man
“Focus on what you can do, then do it with all your heart.” Lois Wilson