There is a tendency in today's society to think that we can 'engineer' culture. They think we could, for example, limit the number of abusive relationships in this world if we simply stopped glorifying said relationships in media. I'm not of this opinion. I don't think unhealthy relationships exist because people see similar things in stories, but rather, I think any relationship is potentially unhealthy and media simply reflects that fact.
While I do think that there are certain people who do get heavily influenced by what they see in movies or read in stories, I think they're probably in a minority. Everyone figures out pretty quickly that love at first sight and happily ever after don't exist in real life quite like they do in the movies. Likewise for the concept of soulmates or 'Mr Right'.
I actually really enjoyed reading Twilight (I don't care it's super trashy and mediocre). But I never for one second thought that their relationship was anything that anyone should ever aspire to in real life. Just like how I enjoy shooting people's heads off in video games, I'm not consuming media for life lessons or tips.
Stories that involve things like stalking, obsessive behaviour, violent sex and any other manner of things aren't mirroring what we want in our real lives. No, they're tapping into deep, unconscious regions of our psyche and letting those emotions flow in a safe, fun way.
People might find it gross, but one of the most popular porn videos consumed by women are rape scenarios. Likewise, one of the most popular for men are one woman with multiple men. What does this say about us? That women secretly want to be raped, or that men actually want to see their partners take on half a dozen studs at once? No, of course not! For many, these images simply trigger a pleasurable series of chemicals to be released in their brains. Why? Some people have some pretty good theories, but the point is, such facts remind us that despite the seemingly civilised culture we've surrounded ourselves with, we still possess powerful, base cravings and urges that we can't fully explain or even comprehend.
Love, sex and relationships in real life is fraught with danger, confusion, real pain. We all like to believe that the decisions we make throughout our lives are purely logical, rational and in our own best interests, but it's my opinion that it just isn't that simple. Multiple parts of our bodies are competing against each other to have their needs catered to. This makes us all do dumb things from time to time. And I think stories like 50 shades and Twilight are just tickle those parts of the brain that we too often like to think we have more control of than we do.