On Monday, Kutcher, 32, was on the Michigan set of Moore's new film The Reasonable Bunch, quietly watching his wife work, and happily accepting her hugs between takes.
Says a set source, "Demi and Ashton got here in the early hours of the morning and you could hear them laughing and carrying on from inside her trailer."
Indeed, if the couple, who will celebrate their fifth anniversary Friday, are at all troubled by recent reports that Kutcher cheated with a 21-year-old, they are keeping it to themselves.
While the Internet buzzed about the alleged infidelity, Moore, 47, "gushes over Ashton on set," says the source.
"She's on the phone with him all the time," says another source. "It's pretty lovey-dovey – lots of 'I love you, baby's.' "
Kutcher arrived in Michigan over the weekend on his way to the Clinton Global Initiative, where the he is set to appear Thursday to launch "Real Men Don't Buy Girls" campaign to end child sex slavery. The pair, who practice a form of Jewish mysticism called Kabbalah, observed Yom Kippur together, breaking the traditional fast at a nearby Applebee's.
While Moore told people on the set that she was "coming off a good weekend," she admitted that the fasting was a real challenge.
"I could never starve myself," she was overheard saying. "I love food too much."