The Twilight star was his usual casual cool self in jeans, hoodie and beanie hat as he jetted into LAX on Wednesday (24 July) carrying his own luggage.
The same day, a picture emerged online that showed R-Pattz with his back to the camera but appearing to plant a kiss on a brunette woman. The angle of the picture makes it unclear, however, as to whether he's simply giving her a friendly goodbye peck.
Rob, who was recently seen hanging out with Beyoncé, had been out at dinner with Mia Wasikowska and Jesse Eisenberg in Toronto when the snap was taken.
According to E! News, however, the picture might not be what it seems. A source claimed the mystery woman could be Rob's latest director David Cronenberg's daughter Caitlin, and if that's true, there's nothing romantic going on: they are just friends.
We bet R-Pattz's legions of female fans are quite happy to hear that!
Given that Rob is so private about his personal life we doubt he'll be clarifying either way, though.
Since splitting from Twilight co-star Kristen Stewart, the British born actor has also been linked to Elvis Presley's granddaughter Riley Keough and more recently, his Map To The Stars co-star Sarah Gadon.
We can't keep up!
Prince George, Joey Essex, One Direction: Wednesday, 24 July's top stories in pictures:
Copyright: WENN Craig Harris