Singer Lisa Marie Presley is adamant her actress daughter Riley Keough would never date Robert Pattinson, because she is "best friends" with the Twilight hunk's ex-girlfriend Kristen Stewart. Reports surfaced in June (13) suggesting Elvis Presley's granddaughter had embarked on a romance with the Brit after they were purportedly photographed together in Los Angeles, just weeks after Pattinson and Stewart were rumoured to have called off their three-year relationship for good. A representative for Keough denied the allegations and insisted she was not the girl featured in the pictures, and now her mother Lisa Marie has made it clear the relationship speculation was completely unfounded. Addressing the claims during an appearance on U.S. talk show Watch What Happens Live on Thursday night (17Oct13), Lisa Marie said, "I will say who she's not with... and that is a complete lie, and the silliest thing I've ever heard, is that she was with Robert Pattinson, because she and Kristen Stewart are like best friends. So that was the craziest rumour that I will put to bed... That was not true." Keough, who struck up a friendship with Stewart on the set of their 2010 biopic The Runaways, has since been spotted back with her former fiance Alex Pettyfer.