New mom Mila Kunis wants baby daddy Ashton Kutcher to tell ex-wife Demi Moore to butt out of their lives!

Insiders say Mila is furious over Demi’s meddling since she gave birth to Ashton’s daughter, Wyatt, on Sept. 30.

“Demi is forever calling and texting for updates on Wyatt,” a source said. “It’s driving Mila nuts!”

Insiders say Mila, 31, has always supported 36-year-old Ashton’s desire to stay on good terms with Demi – especially given her emotional struggles following their 2011 split. “Ashton has always treated Demi with kid gloves because he doesn’t want her to have another breakdown,” explains the insider. “But now Mila has decided enough is enough!”

Sources also reveal the “Ted” cutie is so upset about Ashton’s inability to stop Demi’s meddling that she’s having second thoughts about tying the knot.

Meanwhile Demi has even turned up uninvited at their home!

“It freaked Mila out when she found Demi holding her baby in their house,” added the source.

Mila’s told Demi to stay away from her baby – and to leave them all alone!”