"I've got an important decision to make before I would ever ask Miranda to marry me," Shelton told PEOPLE at a Songwriters Hall of Fame Awards event in Manhattan.
"And that's if I'm okay with getting my ass kicked about once a month every time I make her mad. That's definitely a concern I have, but that's my favorite thing about her is her attitude."
Shelton, whose most recent hit – a cover of Michael Buble's "Home" – reached number three on the Billboard Hot Country Songs chart earlier this year, was divorced from his wife of three years, Kaynette Williams, in 2006.
Fellow country singer and Nashville Star finalist Lambert was recently cleared of assault after a fan accused her of shoving her in a Texas bar.
The couple stepped out together in mid May at the Academy Of Country Music Awards.
While Shelton got his big break in Nashville in 2001 with his single "Austin," the singer says city life isn't for him. He moved into a 1,200-acre ranch in Tishomingo, Okla., two years ago, and Lambert moved six miles down the road.
"[We'd] rather be at home cooking hamburgers or picking corn or something", he says, than living it up in Nashville like many of his country counterparts.
"It's paradise for us there (in Oklahoma) right now."