Twilight is a story of forbidden love. Because Edward is a vampire and Bella a human, Edward technically should consider Bella his prey. While Edward does love Bella, his primal instincts lead him to thirst for her blood. Similarly, Bella's natural instincts should warn her that Edward is dangerous, that she should stay away from him, but instead she craves being near him at all times. For this couple, even kissing is dangerous, yet their passion is so intense that they each claim to have no choice but to be with the other.