I'm all right, I can handle it'. The secret sessions. Anger and evasion may distract from the real problem. They can occupy a night, a day, a week, a lifetime, so in the end you don't have to think about what's really wrong. That's the real joy of blame, it's thoughtless.
People drink for all sorts of reasons.
Many say its their only option. It is hard to choose when you believe you have no choice. Because he doesn't want the grief, that's why. When he hears the front door slam he slips out the back. It's not that his Dad is a bad man, it's just that he drinks a bit much.