Leaving his New York hotel last night, Rob jumped on a flight to LA, surrounded by paps quizzing him about snaps of Kristen taken in LA last week.
But the 26-year-old kept schtum, keeping his frown in place as he finally arrived in LA, rushing through the hordes of paps and jumping into a waiting car.
Rob has a difficult day ahead of him after pictures of Kristen getting into a car with a Rupert Sanders lookalike were leaked yesterday.
And while some sources claim the man in the vehicle was NOT Rupert - who Kristen cheated on Rob with last summer - the pictures are still doing the rounds.
The snaps show Kristen leaving a restaurant over the weekend before climbing into the passenger seat of a black car, believed to be the same model as Rupert's.
It's unclear whether the pictures were taken while Rob was still in LA or after he had jetted off to New York for work.
But an insider has now told HollywoodLife that the man in question is actually just a valet for the restaurant.
They added: "That man is a driver, a valet driver. After he drove the car to the front of the parking area, he got out and the two young women in the photo got into the car.
"That young girl wearing glasses, Kristen Stewart, got into the passenger’s side. She is a regular here and very friendly."
Oh, and any rumours saying she might "reunite" with Rupert are a load of rubbish, according to the same source.
They said: "There is not a chance in hell that she was with Rupert yesterday or anytime recently.
"It wasn’t him and she was not hanging out with Rupert, he has never visited the location, and they were not together."
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