People do tend to imitate what they see. Certainly it's not set in stone and there are always counterexamples, but overall, the trend is to mimic observed behaviour - hence the idea of things like 'leading by example'.

That being said, there's a lot of different types of porn. Saying "I watch porn" is like saying "I read fiction". It certainly tells us a bit about you, but isn't particularly definitive - do you read lightweight trash like Dan Brown, do you prefer mysteries, bodice-rippers, fantasies, war novels, or the complexities of writers like Eco? Perhaps a little bit of everything depending on the mood?