Robert Pattinson is dating Riley Keough, but not in a traditional sense. A source claims they are only friends with benefits, due to his trust issues caused by Kristin Stewart cheating on him when they were together.

"With his schedule and his overall trust issues with girls due to his celebrity and what Kristen did to him, he and Riley are nothing more then friends with benefits," a source close to the "Twilight" actor told HollywoodLife.com.

"He considers himself single, but acts like a couple when he is around her," the source added.

Despite the attitude Rob has, the actor just landed back in Los Angeles and may be spending time with his friend with benefits.

Rob is dealing with his trust issues, which were most likely caused when Kristin Stewart cheated on him with their married director Rupert Sanders.

A few days ago, another source told HollywoodLife.com that Rob, 27, isn't very serious about Riley, 24, who is Elvis Presley's granddaughter.

"Rob will probably be seen with other girls along with Riley," the source said. "He generally considers himself both single to his friends and exclusive when he is with Riley. It's getting very physical between him and Riley, but he still isn't ready to pull the trigger on a full relationship as he will be away filming soon and he doesn't want to ruin something that is blossoming by leaving. He is aware that something still might happen, but he is being cautious. But with a strongly physical relationship that is happening, he knows that can always lead to more, so his mind is everywhere."

On July 22, Rob was spotted kissing a mystery brunette after having dinner when shooting for his new film, "Map to the Stars," wrapped up for the day in Toronto, Canada.