Flaming hot Underworld star Kate Beckinsale thinks her butt's too big! "She has a slim, toned figure that most women would die for. But Kate Beckinsale has demanded a body double for her latest film-because she 'loathes' her bottom. Producers have had to hire a £1,000-a-day nude stand-in after Kate, 34, refused to bare her derriere in a shower scene. In the past the actress, who earns £3.2million for a film, has not been shy of squeezing into sexy clothing and almost showed her bottom in Uncovered in 1994. But a source on her new film Whiteout said: 'Kate has a terrible self-image. She thinks she is fat and she is always complaining how certain outfits make her bottom look big. Of course, the reality is that she has the most amazing body.'" Almost showed her bottom in Uncovered you say? Screen grab after the jump!