Ashton Kutcher is keen to continue making more babies with Mila Kunis

Ashton Kutcher is worried Mila Kunis will "cut him off" from having any more kids once they have a son and daughter.

The Just Married actor revealed he and his wife are expecting a baby boy on Thursday (06Oct16), a younger brother for their two-year-old girl Wyatt. Although he's thrilled to be having a son, Ashton jokes having one of each may mean Mila won't want any more children - and he's desperate for a big family.

"We haven't told anyone, we're having a boy," he grinned nervously to talk show host Seth Meyers. "I was actually hoping for a girl, because first of all our first girl is unbelievable, but also I figured if we had a girl second she might give me one more shot to have a boy. And now I don't know! It's even money, she might cut me off! I want like 12 of them... We're very excited, we're very happy."

And it sounds like Ashton has learned some valuable lessons since becoming a father to Wyatt before welcoming his second child, such as not to swear in front of his tot. The That '70s Show actor recalled a funny story from when Wyatt was around 18 months old and their new dog Ricky peed on the staircase, only for the toddler to hear his reaction.

"I'm getting ready in the morning and Mila's like, 'Ricky peed on the stairwell', and I'm like, (swearing at) Ricky," he said. "And I'm walking and my daughter's right behind me and all of a sudden I just hear (her repeat his swear word)."

Ashton desperately tried to pretend to his little girl that he had used the word fox, not the curse word, but to his disappointment, Wyatt turned to a hole in the carpet and repeated (the expletive).

He thinks he's finally undone his mistake though, adding: "I think I've got her convinced that it's 'fox' now - I'm pretty sure she thinks it's fox."