, star of the House of Lies
and the upcoming Farrelly brothers comedy Movie 43
, graces the April 2012 cover of Women's Health
and opens up about going vegan, her co-star's butt, and what it's like to work with her fianc Dax Shepard
on their upcoming movie, Outrun
.Kristen on butts...
"My favorite things on the planet. I want two round cupcakes, always. I kicked my buns and abs sets into high gear when I knew I'd have to be ...