BumpWatch: Paul Stanley Shows Off Wife's Belly

Paul Stanley and wife Erin debut her bump at the opening of Rimowa on Rodeo Drive on Monday in Beverly Hills, Calif.

Baby girl on the way!

Paul Stanley and wife Erin debut her bump at the opening of RIMOWA on Rodeo Drive on Monday in Beverly Hills, Calif.

The KISS rocker, 59, will welcome his third child with Erin, an attorney, this August — and it’s a girl!

“I may be 59,” he tells PEOPLE, “but the only rocking chair this rocker is getting ready for is the one for my new baby.”

Stanley’s new daughter will join elder siblings Sarah Brianna, 2, Colin Michael, 4½, and Evan Shane, 16, his son from a previous relationship.

RELATED: Baby Girl On the Way for KISS’ Paul Stanley