Life & Style can exclusively reveal that the loved-up duo are already in Cedar Rapids, Iowa, to spend the holidays with the Two and a Half Men star's parents, aunts, nephews, nieces and more.
"They flew in on Dec. 14 and will be there until after Christmas — just like they did last year," a source tells the mag.
The former That '70s Show co-stars will "spend Christmas Eve with Ashton's mom at her house, and then Christmas Day with at his dad's.
"They love hanging out with his big family, and they love spending time with the kids over the holidays," adds the insider.
"Ashton really just loves being the cool, goofy uncle. He appreciates coming home and being just a regular guy."
So far this week, the pair have been spotted shopping around town, specifically at a Target to get some last-minute shopping in.
"They're always so calm and casual when they're here," one eyewitness who saw them at the store tells Life & Style. "You can tell Ashton loves being home and having Mila with him."
Reports have been circulating that the gorgeous A-listers, who've been dating since spring 2012, are engaged and eager to settle down to start their own family.
"I want a family — just, like, one day, not tomorrow," the 30-year-old beauty told Playboy earlier this year, adding, "I want to be a present mom."
Their trip comes nearly three weeks after the actor, 35, finally settled his long, drawn out divorce from actress Demi Moore, 51.
The pair had separated in November 2011 after six years of marriage. Ashton filed for divorce one year later.
Demi then responded with her own filing in March 2013 by citing "irreconcilable differences" and asked for spousal support as well as attorney fees.