Robert Pattinson and Kristen Stewart's relationship 'useful' on Twilight set

THEY are known for being secretive about their relationship.

Source: http://star-magazine.co.uk//breakingnews/view/36460/Robert-Pattinson-and-Kristen-Stewart-s-relationship-useful-on-Twilight-set/

Drea de Matteo Drew Barrymore Ehrinn Cummings Elena Lyons Elisabeth Röhm Elisha Cuthbert Eliza Dushku Emilie de Ravin