Heads up, ladies. Rumors that movie vampire Robert Pattinson is dating his 'Twilight' co-star Kristen Stewart have been swirling for months, bolstered by recent fan-snapped photos of the two looking cozy at a Kings of Leon concert and a tidbit spilled to reporters by Peter Facinelli's wife Jennie Garth: "I can't say [who he's dating]... But I do know." Even so, the British actor told the Daily Mirror: "I don't have a girlfriend. I don't know why."