Kristen Stewart Is Writing an Apology Letter to Rupert Sanders' Wife, Liberty Ross

Oh, let the widespread repentance begin!

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Kristen Stewart is reportedly so guilt-ridden after her tryst with the married Rupert Sanders that she's penning an apology letter to his wife, Liberty Ross.

Rupert has been married to the former model and actress for nearly a decade, and the pair have two children.

"Kristen didn’t feel it was appropriate to issue a public apology to Liberty once the story of her affair with Rupert broke," the source told RadarOnline.com. “Instead, she’s going to do the decent thing and write Liberty a private letter expressing her deepest regret for her actions."

The source continues, saying that the actress now considers the fact Rupert had children and feels the affair was "terribly naive" and feels "awful."

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Meanwhile, she's desperately trying to save her relationship with Robert Pattinson, who is "heartbroken and humiliated."

"I'm not sure they'll be able to recover from this," a friend of the couple said.