"No matter what it is – awards or No. 1's, skeet shooting or fishing – there's always good, friendly competition between us," Lambert said after helping announce the nominations Tuesday on CBS's The Early Show.
Added Lambert, 27, with a laugh, "Sometimes it's not so friendly!"
Lambert may have an edge over her fiancé in the video of the year category: She has two videos – "Only Prettier" and "The House That Built Me" – nominated, while Shelton's "Hillbilly Bone" got one nod.
Overall, Lambert leads the ACM nominations with seven total, including entertainer of the year. But despite the accolades, including the upcoming Grammy Awards, it's her wedding day she's most anticipating.
"We're really busy," she said of squeezing wedding planning into her schedule. "I still have a few months to go but there's a lot going on. I'm excited about all of it, and I'm excited to get married."
"The anticipation of it all is a lot," she said. "I'm kind of ready to say, 'Okay, let's have this wedding and be married.' "
Meanwhile, Shelton is "really excited about co-hosting the ACM Awards with Reba [McEntire]," Lambert said, noting her fiancé's mischievous personality.
"I'm not nervous for him," she said. "I'm nervous for Reba and the audience. You don't have any idea what he might say and it's a live show. They definitely need that five second delay."