Zach and Colton Swon, together known as the Swon Brothers, scored one of the most coveted tour slots of 2016 when Carrie Underwood invited them to join her Storyteller Tour. The real-life brothers tell The Boot that the pairing actually began with a joke.

"We were on the bus, traveling to a gig, and we were texting her," Colton Swon recalls. "We said, ‘Hey, I know you’re going on tour soon. We’ll walk your dogs, we’ll babysit, we’ll do anything, if you need an opening spot.'

"So we texted her, just joking," he continues, "and she was like, ‘Ha ha, I don’t think I’ll need babysitters.’"

"Actually, she said, ‘I don’t think I’d trust you with my baby,'" Zach Swon interjects.

Neither of them expected the country superstar to actually take them up on their suggestion -- but it happened.

"The very next day, pretty much, it was like, agents start calling," Colton Swon says. "We started getting calls saying, 'Carrie’s going to put in an offer for the tour.'

"We’re like, ‘You’re kidding me?’" he adds. "This is, like, going to be the biggest tour of 2016. She hasn’t toured in, like, three years."

The duo knew that Easton Corbin was already booked as Underwood's opening act, so they didn't think there was another spot available for them.

"Every time I’ve seen her, she’s only taken one other act," Colton Swon explains. "To be a third act on the tour, it’s like, ‘Thank you.’ That’s a good friend to have.

"She’s so sweet," he concludes. "... She’s just as sweet and genuine as they come. That girl’s been awesome to us."

Both Underwood and the Swons are Oklahoma natives and have known each other for years.

"We grew up together. My brother went to college with her. We all did these little country family shows together. We grew up 10 minutes from each other," Colton Swon notes. "She was always winning every talent contest growing up."

After Underwood won Season 4 of American Idol in 2005 and released her multi-platinum Some Hearts album later that year, they lost contact for a bit ("She became huge, and her numbers changed, and, trust me, I see why," Zach Swon says). While they were out of touch, the Swon Brothers landed a spot on Season 4 of The Voice, and they reconnected with their friend while she was in Oklahoma on her Blown Away Tour.

"It was right after the audition, and we had made Blake Shelton’s team, but we couldn’t say anything because the show wasn’t going to air for a while ... We were under strict orders not to say anything, but we were like, ‘Maybe we could get some advice from her because she’s been on TV,'" Zach Swon shares. "I remember going back and saying, ‘Hey, good to see you. It’s been a long time. And, we want to let you in on a little secret. Do you have any advice for us?’ She said, ‘Well, I was on American Idol, so I don’t know anything about The Voice.' We were like, ‘Okay, well, just about TV in general.’

"After that, one day, I just got this message, I think on Twitter, and she said, ‘Hey, you guys are doing great. When you get to Nashville, because you will be in Nashville, give me a call, and we’ll take you to dinner.’ And literally, the week we moved, I got this random text message, and her and [Underwood's husband] Mike [Fisher] took us to dinner," he continues. "Ever since then, we’ve kept in touch. Last year, I gave her an invite to my brother’s birthday party that I threw him. She showed up."

Not only did Underwood show up, but she was the last guest to leave the party. Since then, the singers have formed a close friendship, which makes their upcoming trek especially meaningful.

"The fact that she thought about us the next year, after the baby stuff was done, means the world to us," Zach Swon confesses.

The Storyteller Tour -- Stories in the Round is scheduled to begin on Jan. 30 in Jacksonville, Fla. A list of all of the Swon Brothers' upcoming dates is available on their website.

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