Twilight star and star of the Joan Jett biopic The Runaways, Kristen Stewart, has reportedly been bombarded with hate mail from angry fans who  believe she has been cheating on her Twilight costar boyfriend Robert Pattinson, according to Perez.

Fervent female fans of the hugely popular vampire franchise are crucifying Stewart for cheating on Rob with Michael Angarano.

"Kristen has had letters from girls who don't think she's treating Rob fairly because she's dating Michael Angarano," a source told the tabloid the National Enquirer.

"The fans love Rob, and they love the idea of Kristen and Rob romancing off-screen. But they don't like the idea that she might be hurting their favorite young actor by stringing him along while she is still dating Michael."

"The letters, which are being sent to the studio, accuse Kristen of being heartless by dating both guys."

Meanwhile, sources close to Kristen have been arguing that the actress and Pattinson have never really been an item.

"Kristen cares very much for Michael," said the insider, "but she also has a crush on Rob. And while Michael wishes Kristen would get over Rob, he isn't ready to pull the plug on their relationship."

Did someone say drama? Maybe Kristen should ditch them both and hang with the girls.

Apparently Kristen is upset that fans are mad at her and made it a point to let them know how she "genuinely cares for both Rob and Michael - and doesn't want to hurt either."

The source also stated: "Kristen hopes fans will understand how she feels and stop sending her hate mail."