Montana Boyz on Kristin Cavallari's romance with member Mark Estes The Montana Boyz spoke to Fox News Digital at the CMT Music Awards about how Mark Estes' relationship with Kristin Cavallari has helped the group. NEW You can now listen to Fox News articles! Kristin Cavallari has a new deal breaker when it comes to dating, after previously being in a relationship with a man 13 years younger. On this week's episode of "Let's Be Honest with Kristin Cavallari," the host had actress Sarah Shahi on