Kristen Stewart and Rob Pattinson are officially back together. A month after reconciliation rumors surfaced, the two were finally spotted out in public together.  Us Weekly reported that the Twilight stars made a low-key appearance at the Chateau Marmont over the weekend for a friend's birthday party. One witness told the magazine that the two were "whispering very close and intimately" throughout the evening.  A source close to the couple explained, "They're afraid of backlash, so they're keeping things on the down-low."  However the two will step out together in serious fashion soon as they begin promoting the final installment of the Twilight Saga.  To see the pic, click here!