Kristen Stewart only just got to don fangs in the final Twilight Saga installment. So, it would only make sense that fans crave more vampire K.Stew. But what does Bella Swan, er, Bella Cullen think about it? “I’m not sure,” Stewart told us when she hit the black carpet at the premiere of the final Twilight film, Breaking Dawn Part 2 Monday. “It would have to be pretty special.” You know, I th…