Ashton Kutcher spent his Christmas holiday with screenwriter Lorene Scafaria whom he had hooked up with before splitting with Demi Moore, according to Us Weekly.

A witness tells the mag that Ashton and Lorene were cruising around the city in a Porsche and even "held hands" during their spaghetti dinner. They also were seen snapping photos together at the Leaning Tower of Pisa.

Kutcher, 33, Tweeted this photo with pal Matthew Mazzant and Scafaria ... whom at one time was linked to The OC actor Adam Brody.

A source close to Scafaria adds, "Ashton started seeing her while each was in a relationship."

Reps for both deny these claims and tell Us, "They're just friends."