Ashton Kutcher and pregnant Mila Kunis are expecting a baby girl, source reveal exclusively to Us Weekly Credit: Fox/Getty Images

Ashton Kutcher will soon be outnumbered 2-to-1 in his household -- because his pregnant fiancee, Mila Kunis, is expecting a baby girl, multiple sources confirm exclusively in the new issue of Us Weekly. Although the daughter-to-be will be the first child for both Kunis, 30, and Kutcher, 36, the Two and Half Men hunk "got plenty of practice with Demi's girls," one pal notes. Indeed, for six years, Kutcher was famously stepdad to Rumer, 25, Scout, 22, and Tallulah, 20, ex-wife Demi Moore's kids with Bruce Willis. Click here to see more pics of Mila's bump.

Ecstatic for impending fatherhood, "Ashton is doting on Mila," another friend notes of the reformed party boy, who's already lining up playdates with the couple's old That '70s Show costar Danny Masterson and Fianna, his 2-month-old daughter.

Although Kunis has remained completely mum about her pregnancy, the evidence was undeniable at this past Sunday's MTV Movie Awards, where her baby bump was obvious (and adorable!) in a loose-fitting black Thakoon dress. "Mila absolutely loves being pregnant," another pal says.

For much more on how the super-couple is getting ready for baby (crib and diaper shopping is underway!), pick up the new issue of Us Weekly -- on stands Friday!