Christina Aguilera: 'We'll Definitely Have More Kids'

By Courtney Rubin

10/14/2008 at 05:00 PM EDT

Her first child, son Max, is just 9 months old, but Christina Aguilera is already thinking about baby No. 2.

"Absolutely, we'll definitely have more kids," she told PEOPLE at the Africa Rising concert in London Tuesday. How many? "I don't know. We'll play it by ear."

For now, the singer, 27, is enjoying her time with Max.

"I'm in love with my life," she says, although parting with her son to perform can be a drag. "But Mama has to work, Mama has to do a job."

She adds, "I think it's important to share what I love – what makes me me – with my son. So. I change diapers and I breastfeed him and I play with him and then I work. I want to show Max everything about me."

Aguilera, who married music exec Jordan Bratman in 2005, says Max inspired her upcoming album. "It's all about color and life. Everything's a playground for him. Everything is color and fun."

How did Aguilera regain her body after baby? "You try," she says. "Working out. Trying to eat as healthy as possible. I'm a junk food queen."