The 22-year-old actress has publicly apologised to her boyfriend of four years Robert Pattinson after she was caught in a steamy make-out session with her `Snow White And The Huntsman` director Rupert Sanders and Lady Gaga has weighed in, telling people to leave them alone. She tweeted: "Geez this kirstew rob stuff is brutal. Makes me sad the way press acts. Hope they`re ok (sic)." Kristen`s statement on 25.07.12 read: "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 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.