The problem is, learning about sex from porn is like learning about firearms from action movies. Action movies sacrifice realism for the sake of storyline or a really cool explosion. Action movies don’t teach you gun safety. Action movies don’t talk about alternatives to violence. And action movies use some tropes—such as the infinite ammo supply—that may move the story along but don’t reflect reality. That’s not a problem, as long as everyone treats them as entertaining fantasies.
Unfortunately, for many young people becoming sexually active today, the entertaining fantasies of mainstream porn are the teacher they’ve spent the most time with, and mainstream porn is a terrible teacher.
Link