It's not even nepiophilia!

In the movie Jacob sees a vision of the future the first time he sees Renesseme (or whatever the hell her stupid mother named her.) He sees her as a grown up (or about 17 I suppose) and gets the idea that he has to protect her. Since the other werewolves are coming to kill her, he imprints on her as it is apparently sacred law among werewolves that they cannot harm a being that has been imprinted upon.

Of course, the actual details matter little to Twi-haters who just want to add fuel to the fire. I'm no lover of the films myself nor have I read any of the books, but I do have more than 3 brain cells to bang together. Anyone who even remotely paid attention during the movie (a Herculean feat in and of itself) would come to the same conclusions.