MOM-to-be Mila Kunis gave her fiancé Ashton Kutcher an ul­timatum – dump his beloved bachelor pad or she’d refuse to say “I do!”

The “Two and a Half Men” hunk, 36, balked at first but eventually gave in, said a source.

“Mila loves everything about Ashton except that house,” revealed an insider.

“She says the place is great, but she didn’t like thinking about the women that Ashton bedded there.

“She told him to make his mind – it was either her or the house.”

In 2012, Kutcher paid $8.4 million for his lavish Hollywood Hills home, which boasts a the­ater, home gym, retractable glass walls and an infinity pool.

Besides being haunted by the ghosts of girlfriends past, Mila felt it wasn’t kid-friendly, noted the

 insider. “Mila told Ashton to grow up and get serious,” added the source. “She said it would be impossible to baby-proof the place, and she wanted a home that was more suitable for a family.

“She made it clear she wouldn’t marry Ashton if he insisted on keeping it. He didn’t want to give it up. But in the end, Ashton wants nothing more than to please Mila.”

He listed the five-bedroom, eight-bathroom mansion for $12 million. Meanwhile, the parents-to-be have plunked down $10 million for a 7,351-square-foot, three-bedroom, four-bath home in an exclusive gated community in Beverly Hills.

“Black Swan” beauty Mila, 30, recently con­firmed their engagement to talk-show host Ellen DeGeneres, and she also revealed she’s chosen natural childbirth with Kutcher’s sister-in-law, Katie Hightower, serving as her midwife.