Any teenage guy or girl should be left alone when discovering sexuality through porn stuff. It's not the only way nore the best way but it's one way. And there are soft porn movies that are far from disrespectful of either gender.
Of course, women are not always respected as they should be in porn films but this can be talked over and balanced with other approaches.

Also parents shouldn't think they must and can deal with this phase alone. Friends, brothers and sisters can be a great help. As long as it comes up naturally, any talk is good, but I think input from both men and women is necessary. You might still need to provoque a conversation, and then contraception and/or protection are easy subjects to start with and see how much is already known or misunderstood.

And of course, discovering by oneself is also fine.

As long as you don't put it under their noses when they're not asking for anything, or forbidding anything sex related to be seen, heard or read, the learning will happen by itself in a natural way.
Be open, supportive and responsible.

Ponrauil