Marnie Simpson has revealed that she and fiancé Casey Johnson have "fallen out" with his brother Chet and girlfriend Helen Briggs for a second time.The 30 year old was asked about her and 26 year old Casey's relationship with Chet and Helen as she answered questions from her fans during an Instagram Q+A on Monday evening. When asked whether or not the couple had fallen out with Chet, 31, and Helen, 26, Marnie openly told her 4.7million followers: "We're just very different people, and have absolutely nothing in common." OK! has contacted representatives for Marnie, Casey, Chet and Helen for comment.