The 22-year-old beauty was photographed in a passionate clinch with her married `Snow White And The Huntsman` director Rupert Sanders despite her relationship with `Twilight Saga` co-star Robert and she has released a statement admitting her guilt.

She said: "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 jeopardised 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."

Sources close t to the actress insist she wasn`t having an affair with Rupert and it was a fleeting mistake.

An insider said: ""Kristen is absolutely devastated. It was a mistake and a complete lapse in judgment."

Kristen and Robert, 26, have been dating since meeting on the set of `Twilight` four years ago, in which they play vampire Edward Cullen and his love interest Bella Swan.

Photo - from http://hollywoodite.com
sections: Celebrities