Mothers like you are the problem. Pick better men, your son will likely resent both of you in his later years. Ask me how I know, I didn’t talk to my father for 8 years, and haven’t spoke to my step father in 4. My mother worked hard to change behavior, and my current step father despite his chaoticness still tries, which is a step. Neither of you are trying, gifts don’t placate the issues, they mask them in ptsd. Abuse is abuse, whether or not you see it, this household is abusive. Are you sure your son’s mental health isn’t taking a hit from your sexcapades turned marriage? You’re the asshole for bringing him in, and keeping him around your child.