Remember that affair between Kristen Stewart and director Rupert Sanders a while back? Yeah, so does his wife. Actress Liberty Ross has filed for divorce from Sanders about six months after his fling with the much younger Stewart went public, reports TMZ. They have two kids, ages 5 and 7, and she is seeking joint custody along with spousal support. Stewart, meanwhile, has had better luck making amends with Twilight co-star Robert Pattinson.