Are Robert Pattinson and Kristen Stewart rekindling their romance?

Less than a week after it was reported that Pattinson was shacking up with Stewart's 'The Runaways' co-star Riley Keough (and also with Caitlin Cronenberg), R-Pattz was spotted at K-Stew's pad.

X17 snagged photos of Pattinson's Durango parked right in front of Stewart's Los Feliz, Calif. home. He reportedly stayed for about two hours before leaving.

A witness told X17, "Rob looked nervous on his way to visit Kristen. He was trying to be discreet so no one would see him." The nervousness could be explained by the fact that, well, paparazzi were and are hounding his every move ... or by the fact that he may have been hooking up with one of Stewart's pals.

While we're sure Twihards and Robsten shippers are gunning for a romantic reunion, it's also possible that the pair are just tying up some loose ends post-split. X17's sources are optimistic for a Robsten reunion, though, citing their conflicting schedules for why they haven't seen one another often lately.

On the bright side, this does dispel some of the chatter that the couple were a PR relationship designed to propel 'The Twilight Saga' into box office blockbuster territory. Goodness knows it worked better than the scripts did.