Kristen Stewart not-so-faithful to Robert Pattinson

Though her vampire transformation is eternal, actress Kristen Stewart’s actions show that her love and compassion in her relationship with her heartthrob boyfriend Robert Pattinson might not be forever.

The 22-year-old cheated on Pattinson with Rupert Sanders, 41, the director of Stewart’s newest feature-film, “Snow White and the Huntsman.”

Us Weekly describes the act, which was caught on camera, as a “steamy rendezvous,” while a source close to the situation tells People, “She wasn’t having an affair with Rupert. It was just a fleeting moment that shouldn’t have happened."

By the way: Rupert is married.

Yet for a sweetheart like Stewart, a wrongdoing like this doesn't go without an apology. According to People, Stewart has issued a public statement pointed specifically as an apology to Robert.

"I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected. This momentary indiscretion has jeopardized the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I’m so sorry,” she said.

Rupert, too, released a public apology. "I am utterly distraught about the pain I have caused my family," Sanders told People. "My beautiful wife and heavenly children are all I have in this world. I love them with all my heart. I am praying that we can get through this together."

The British director is married to actress-model Liberty Ross. They have two children.