|Stewart with Pattinson at the Twilight Premiere|
The 'Twilight Saga: Breaking Dawn Part 2' co-stars - who recently rekindled their relationship following the 22-year-old actress's "momentary indiscretion" with her 'Snow White and the Huntsman' director Rupert Sanders last summer - are planning to spend the festive season apart after she spent a "nerve-wracking" Thanksgiving with his family in London last month.
An insider told Heat magazine: "The family were smiling at Kristen and looking totally at ease on the red carpet, (during the 'Twilight Saga: Breaking Dawn Part 2' premiere) but back at the family home over the following weekend things were more difficult.
"They had a meal on Thanksgiving , and it was nerve-wracking for Kristen. She felt very uncomfortable and Rob's sisters couldn't be completely welcoming. It won't go back to normal straight away, even if Rob has decided to try again.
"Rob's mum wanted him to spend Christmas with them in London and, before their trip to the UK, that had been his and Kristen's plan. From London, they were going to fly to Mexico for New Year.
"Rob's family made it clear that they really want to see him over Christmas and, after the intense promotional tour for Twilight, Rob liked the idea of spending time alone with his family."
A source previously revealed that the couple were still in the process of rebuilding their relationship following her affair but Kristen is making a huge effort to win back his trust.
The source said: "She is working hard at the relationship."