"They don't see me as famous," Spears tells ET's Nancy O'Dell in an exclusive interview airing Monday.
"They're really into skateboarding right now," she adds. "They're not into celebrities -- they're into celebrity skateboard people. So mom's show business thing isn't really their interest."
Still, Spears' sons -- Sean Preston, 12, and Jayden James, 11 -- are happy to be joining their mom on the road as she continues her Piece of Me tour in North America and Europe.
"They enjoy it," Spears says, recalling one of her kids' adorable reaction to hearing a remixed version of her song on the radio. "He's like, 'Mom! That is so cool!'"
Spears' new tour is her first since 2011's Femme Fatale Tour and the conclusion of her hugely successful Piece of Me residency show in Las Vegas last December. Being on the road, Spears says that staying fit is a natural process.
"This round of shows that we are doing on tour, they are back-to-back," she explains. "I don't have any time apart besides flying, so it's really just the show itself is going to keep me [in shape]. ... My show is a workout in itself. It keeps you really strong."
More than that, Spears says that her priority these days is simply "to be a happy person."
"It's really important to spread joy," she says. "It's contageous. I think that's really sexy for women."
Spears is currently launching a sexy new perfume with Elizabeth Arden called Prerogative, available at Walmart and Kohl's. For more from ET's exclusive sit-down with the star, tune in to Entertainment Tonight on Monday.