Well, think it through.

Suppose you tell somebody from the close circle of friends. Somebody you trust. What it he reacts the way Adam did? Would you tell the friend that you do not buy things like that? if that is all you would get from the interaction, would it not make more sense to never start interacting?..

... or, say, the friend will take your position and that is that of judgment and criticism. And, let us say, suggest that you go cold turkey or practice 12, 24, or 36 steps in order to get out of your situation. Or something along these lines. But you have already tried 12 or whatever number of steps... did not work.

So, what would be the point of telling the friend about porn if all you can expect to hear is that (1) either what you are doing is OK, (2) or that you need to take steps ABC to stop doing what you have been doing.

You do not want to hear (1) because you do not buy that, nor do you want to hear (2) because you know it would not work.

What else might you hear that you might actually like to hear? think things through before acting.