Appearing at the Country Music Association Music Festival in Nashville, Urban told members of the crowd how he and the "Golden Compass" actress have been besieged by fan gifts for their first child together, People.com reported Saturday.

But after Urban had to have someone explain what a "onesie" is, the "Stupid Boy" star admitted he was still learning the language associated with parenthood.

"I'm learning a new vocabulary," he said during Friday's festival. "We also got a tiny T-shirt that says 'I crawl the line' that we like a lot."

The singer told People.com that while he loves having Kidman on tour with him, they will have to discuss whether their child will become a tour roadie in the near future.

"We'll just have to see what works for us," he said.