ET spoke with the country superstars backstage at Rabobank Arena in Bakersfield, California, during their Soul2Soul World Tour on Saturday, just days ahead of their 21st wedding anniversary. The two tied the knot on Oct. 6, 1996, after meeting earlier that year when Hill opened up for McGraw during his Spontaneous Combustion Tour.
According to Hill, no anniversary gift is needed from her handsome husband.
"He's good. He doesn't need to get me anything," Hill told ET's Keltie Knight. "Honestly, do you, baby? He's good at giving gifts and making surprises."
"That's the best gift ever," Hill cracked. "That's amazing. I get to do that four-hour workout with you? No, thank you. That's my gift -- I don't have to do that workout with you."
On a more serious note, McGraw gushed about getting to see his wife perform every night, admitting he's still in awe of her.
"For me, it's hearing her sing every night -- that's the best part about [the tour]," McGraw said. "Because she's not out there singing much... To see her up on stage, having a great time and just belting it out? I mean, I always say it: when I'm on stage with her, it's like NASCAR trying to keep up with an Indy car. She's just that good. So, to watch her sing and see what she does is pretty inspiring."
"My hot wife, man," he sweetly added.
Even so, the two also have a sense of humor about enjoying their private time.
"I'm going to go on a man vacation after this is over," McGraw said, responding to Dolly Parton's advice that the secret to her long marriage is not spending too much time together.
"I need a girl vacation, actually," Hill added. "I am surrounded by girls, but I love that. We have a great time in my dressing room."
Of course, McGraw said he stays clear of that area of the tour!
"Yeah, I try to stay out of that dressing room," he noted. "It's all girls in that dressing room."
Hill and McGraw are releasing their highly anticipated first joint album in November. For fans who can't get enough of the couple's tour, Showtime is airing behind-the-scenes footage of their tour as well as concert performances, premiering Nov. 17.
Clearly, the couple is more in love than ever after more than two decades of marriage and raising three daughters together -- 20-year-old Gracie, 19-year-old Maggie and 15-year-old Audrey. Earlier this month, McGraw wished his wife a happy fiftieth birthday with a romantic Instagram message.
"Happy birthday to the most beautiful girl in the world," McGraw wrote. "You are the most remarkable person that has ever been in my life.... Our daughters could not have a better role model. I am truly in love with you more everyday. Can't wait to see what 'the rest of our life' has in store for us."
Watch the video below to see their cutest moments throughout the years.