Twilight co-stars Robert Pattinson and Kristen Stewart have been very serious about not being a couple and how they're just friends and all.

And Robert has recently claimed that he can't even get a girlfriend (poor lamb). But the pair were spotted leaving a posh Hollywood hotel together... in the very early hours of the morning.

Onlookers claim that the couple... sorry, pals, emerged early in the morning for a quick bagel before heading off to a screening of movie New Moon at Hollywood's Deluxe Laboratories.

Which, we guess, sounds perfectly innocent and the kind of thing co-stars that are just "really good friends" do.

But a sneaky source reckons he or she saw a spot of smooching going on.

The source told Us magazine: "Rob wanted a cigarette so he went outside with Kristen for about 15 minutes.

"They were hugging, as Rob was smoking his cigarette and then he leaned down and kissed her on the lips. He had his arm around her almost the whole time."

Where are the paps when you need them, we ask?

To see what Kristen may or may not be missing, take a look at Robert Pattinson's photo shoot for Vanity Fair...