The laundromat, of course.
The country superstar says she insists on doing her own laundry and grocery shopping, even while on the road.
"It makes tour life a little difficult because those are things that I really don't have time to do," Underwood, 29, tells Oprah Winfrey on Oprah's Next Chapter airing Sunday. "So that’s what I do on my days off. We go to the laundromat. I get my quarters, we go to the laundromat and go do our laundry."
"I just don't like other people doing my laundry," Underwood adds. "It freaks me out."
Despite the fact that Underwood and her husband, hockey player Mike Fisher, apparently maintain their domestic routine even while she's touring the country, the American Idol winner says it took her a while to adjust to married life. The couple wed in 2010.
"At first it was weird," Underwood admits. "Sometimes I still have those moments where I can't believe I'm married. I spent 27 years not being married and I kinda got used to it."
Still, Underwood says, she's slowly but surely embracing the adjustment.
"The more I do it the more I’m able to think more of 'we,' " she tells Oprah. "For the first year of our marriage I still would give people gifts and write 'Love, Carrie,' and I’m like, okay, now I'm 'Carrie and Mike.' There's two of us now. But I’m getting better all the time."
While Underwood says she and Fisher aren't looking to expand their family any time soon, they definitely plan to have kids, eventually.
"He's going to be the best dad ever," Underwood says of Fisher. "And that makes the whole parent situation seem much, much better."
As far as how many children they plan on having, Underwood tells Oprah: "I think two is a good number … he's like, 'I want seven.' "
Underwood and Fisher's full interview airs Sunday, May 20 at 9 p.m. EST on OWN.
George Burns / OWN