Keith Urban Serenades Nicole Kidman for Her Birthday

Keith Urban might have been a day late, but he definitely wasn’t a dollar short when he serenaded pregnant wife Nicole Kidman in Chicago this weekend.

Saturday night, the country star – who opened for Kenny Chesney at Soldier Field – prompted the crowd of over 50,000 to sing along to “Happy Birthday” in honor of Kidman, who turned 41 on Friday.

The glowing mom-to-be smiled offstage, her hair pulled back, when Urban introduced her, according to the Chicago Sun-Times.

Kidman and Urban are expecting their first child together any day now.