Ashton Kutcher and Mila Kunis welcome baby boy

'She’s the greatest mom'

Ashton Kutcher and Mila Kunis have welcomed their second child. The couple, who married last July, are already parents to two-year-old daughter Wyatt Isabelle.

'Ashton genuinely lights up when talking about Wyatt and the little one on the way,' a source close to Kutcher, 38, tells PEOPLE. 'Everything about being a father is natural to him.'

Back in October, the Bad Moms star, 32, shared her excitement about expanding her family, telling Business Insider, 'Yeah! Absolutely, for sure.'

Though transitioning from one child to two may be laborious for some, the mother-to-be told Entertainment Tonight in May that she’s mastered the 'balancing act' of being 'a great partner, a great wife and a great woman.'

'I know that when we decided to have a kid, we were ready to no longer be selfish — at least start the process,' Kunis said. 'Because innately, as humans, we’re very selfish people, and we really wanted to have a family.'

She added, 'Having this little human to raise … it was a balancing act, and then you learn how to be a great partner, and a great wife, and a great woman, and be yourself, and still be responsible for a living child. It’s definitely a learning process.'

'She’s the greatest mom,' The Ranch star has said of his wife. 'I go to work every day, and I come home and she’s perfect. And it just seems like everything went amazing. And I know that something probably didn’t go amazing, but she never tells … it’s unbelievable. She’s incredible.'

— Karen Mizoguchi with reporting by Mary Green and Lizz Leonard

From the editors of People