The 22-year-old actress admitted to have cheated on Pattinson with married director Rupert Sanders three months back, reported People magazine.
"There's still healing to do and trust issue but Kristen will do whatever it takes. Robert never stopped loving her, so took her back," a source said.
While the two have been busy doing separate promotional duty for the last film of the vampire series "Breaking Dawn Part 2", their much-anticipated red-carpet reunion is set to take place at the film's November 12 premiere.
The couple were spotted here early Friday morning, leaving a Prince concert at Sayers Club in Hollywood.