The 32-year-old Black Swan star is expecting her second child with the actor - a baby brother or sister for the couple's two-year-old daughter Wyatt, who was born in October, 2014 - and Mila intuitively knows her family is set to expand even further after she becomes a mum again later this year (16).

"I've always said this, I think you know when your family is complete," she notes during an appearance on U.S. presenter Ryan Seacrest's radio show on Friday (29Jul16). "After we had Wyatt, the second that I gave birth, I was like, ‘I know that we need to have another baby'. We both knew it, we just felt it."

"And so I always say after the second one, we’ll know if we need to have another one," she continued. "I really do believe you know when your family is complete."

Being pregnant for the second time is leaving Mila feeling "really good" right now, but she is facing a unique parenting issue related to her own bad habits. The star loves to use curse words when she speaks and now that Wyatt is two her potty mouth is becoming a problem.

"It’s so hard," she admits. "I try to work on it daily and my daughter is at a place where she’ll mimic the words that I say, so it didn't really matter up until, like, two months ago when I said a certain word and she said it back."

However, when it comes to cussing, Kunis has given herself a break, motivated by the message of her new comedy Bad Moms.

"I think we, as women, put too much pressure on ourselves to have everything and look a certain way and act a certain way and it’s impossible," she asserts. "There’s no such thing as a perfect balance. I hope this movie, for lack of a better term, takes the p**s out of it."