Kristen Stewart, who’s never been too friendly to the media, blew up at photographers in Australia because of her stressful relationship with Twilight costar Robert Pattinson, a source told BettyConfidential.

“Rob and Kristen’s relationship was going fine,” said the source. “But now that their movie careers have taken off in different directions and different countries. It’s taking a toll on their relationship. It’s not easy to be apart like that and maintain a close relationship. It’s strenuous.”

At one point, Kristen came out on her hotel balcony and gave photographers the finger.

She was in Australia for a hectic promotional appearance with Taylor Lautner. Rob has been shooting a movie in London, and Kristen was clearly missing him.

Read Kristen Stewart: “My Life is Very Good”

Says the source, “They only get to talk by phone, and nine out of ten times one of them is interrupted. It’s hard to have a full conversation. Issues get put off – even just small talk gets put off. They can never finish a conversation unless it’s the end of the day and even then they’re too tired to talk."

"Their last conversation before Kristen headed to Australia was an argument, and she couldn’t get a hold of Rob when she landed in Sydney, so she’s left hanging again. And, when the paparazzi started harassing her and following her, she lost it. She’s never thrilled with the photographers taking her picture, but this time she was really in a bad mood.” Taylor took Kristen out for a jet boat ride on the Sydney Harbour to cool her down, which helped, says the source, But when she saw photographers waiting for her at the dock, she blew up again.”

Now, Rob’s back in the States—but Kristen is still traveling.

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