Getty Images for Stagecoach

So country; so cute!

Ashton Kutcher and Mila Kunis hit up the Stagecoach Music Festival in Indio, Calif. on Friday ... and they brought along their little baby-to-be!

Mila sported a tiny baby bump in a tight black tank with an appropriate plaid shirt on top, which Ashton paid homage to his home state of Iowa with his Coca Cola-inspired tee and wide-brimmed cowboy hat.

At one point, the Two And A Half Men star dipped his lady during a playful dance ... but it wasn't all fun and games. Ashton took to the sawdust dance floor with some serious line dance moves in his black alligator cowboy boots. This country boy's no amateur! Yaaaahoo!

Getty Images for Stagecoach