I'd just like to be the contrary voice here. Certainly it *could* be ASPD, but you said he had ADHD.

First, it's not unheard of for autistic people to be unfaithful. There is a stereotype of autistic people of being scrupulously honest, and frankly its a little more complicated than that. Even if you just consider autism, they can frequently develop odd viewpoints about relationships because they have profound issues with cognitive empathy... and those can include infidelity.

Pathological lying isn't a typical feature of autism, but lying can go hand in hand with infidelity... its kind of a necessity. Autistic people don't have affairs by accident, and they do hold responsibility for those, but there are, very frequently cognitive distortions involved that have structured the need.

ADHD (and OCD) are a very common comorbidities with ASD. With ADHD sexual relation issues are pretty common, due to impulsivity. The ADHD combined with ASD can cause very significant self-esteem issues, which can lead to a whole host of very odd defensive behaviors... and again, there is responsibility for harmful stuff like infidelity, but there are also disorder-based reasons why the behavior happened, that isn't "I do what I want, and don't care who I hurt."

Your mentioning that you were telling him what he couldn't do, and him overtly complying and covertly rebelling is not very ASPD. In that case he'd very likely become enraged (while being charming for the remainder of the time.)

I wouldn't be quite so quick as everyone else here to immediately say "sociopath." It is a possibility, but the autistic constellation disorders mentioned certainly don't preclude the behavior here.

From what I can see, he might be driving this divorce and this all might be moot, but if he does have ASD and ADHD, and has had no treatment, he's been living in a pretty hostile world, and isn't automatically deserving of being ostracized.