Blake Shelton, right, and Miranda Lambert arrive at the Warner Music Group post-Grammy party on Sunday, Feb. 10, 2008, in Los Angeles. (Photo/AP)
Miranda Lambert and Blake Shelton perform "It Ain't Cool to be Crazy About You" at the ACM Artist of the Decade All Star Concert on Monday, April 6, 2009, in Las Vegas. (Photo/AP)
In this June 9, 2010 file photo, Miranda Lambert and Blake Shelton attends the 2010 CMT Music Awards in Nashville, Tenn. (Photo/AP)
Miranda Lambert and Blake Shelton pose in the press room during the 44th Annual Country Music Awards in Nashville, Tenn. Wednesday, Nov. 10, 2010. (Photo/AP)
In this Nov. 9, 2011 file photo, Blake Shelton and Miranda Lambert arrive at the 45th Annual CMA Awards in Nashville, Tenn. (Photo/AP)
Miranda Lambert and Blake Shelton hug after singing "America the Beautiful" before the NFL Super Bowl XLVI, Sunday, Feb. 5, 2012, in Indianapolis. (Photo/AP)
Miranda Lambert and Blake Shelton arrive at the Pre-GRAMMY Gala & Salute to Industry Icons with Clive Davis Saturday, Feb. 11, 2012, in Beverly Hills, Calif. (Photo/AP)
8.Miranda Lambert , right, and Blake Shelton arrives at the 47th annual CMA Awards at Bridgestone Arena on Wednesday, Nov. 6, 2013, in Nashville, Tenn. (Photo/AP)
Blake Shelton, left, and Miranda Lambert arrive at the 57th annual Grammy Awards at the Staples Center on Sunday, Feb. 8, 2015, in Los Angeles. (Photo/AP)