Kristen Stewart and Robert Pattinson**'s relationship is still a bit rocky.

Though Pattinson, 26, took his girlfriend, 22, back after her July fling with director Rupert Sanders, sources tell Us Weekly the Brit is still haunted by her betrayal. And with the scrutiny that accompanies a month of press for The Twilight Saga: Breaking Dawn - Part 2, Pattinson is acting out in unseen ways.

Once at Stewart's beck and call, "Rob is at a point where he sometimes ignores her. He'll go out and won't respond to her calls or texts right away," says a Stewart insider. "Things will be strained for a while."

Until recently, Stewart's philosophy had been to grin and bear whatever it takes to win back her man. The usually reserved star issued a frantic public apology and made tearful pleas for forgiveness to his older sisters. Now that she's back in Pattinson's good graces, they "hang with his friends more," says a source. "She knows she has to go along with it. She is working hard at the relationship."

Indeed, Stewart reportedly bonded with the actor's family in London over the Thanksgiving holiday. The twosome were spotted arriving together in New York's JFK airport on Friday, Nov. 23.

For the relationship to survive post-Twilight (next for him is Queen of the Desert with Naomi Watts, and she is in talks for the Ben Affleck drama Focus), friends say they will have to trust each other.

Says the source, "If they are able to work out being apart while Kristen is filming with Ben or whomever, then they have a shot."

This article originally appeared on Usmagazine.com: Kristen Stewart "Working Hard" on Relationship With Robert Pattinson