Boys need men other than their fathers to mentor them. Finding these men, on the other hand, is the job of the father.
Some messages land easier than when they come from someone else. Even if your son respects you and is obedient, other men he respects will be able to slide things into his brain easier than you. Your voice might be too familiar. He’s so used to your exhortations that they roll off his ears like water on a duck, and not because he disrespects you, but because he’s human.
This can be particularly true for porn and other sexual issues. He will feel ashamed and he doesn’t want to be ashamed in front of you if he is struggling. He wants a way to save face but still have help being obedient. This is where men you trust can step in. Ideally, an older man from your church, maybe a pastor.
This means he needs to know some of the older men already and be involved. So start taking him to lunches and events with you as soon as it’s appropriate.
One father I know asked a few men to write a letter to his son when his son turned 18. These were men the son knew and respected. Almost a decade later, that son still has those letters.
It makes a difference.