How's this for a Christmas Eve proposal? Guided by a trail of lights set up under the glittery Toronto sky, Dean McDermott led his girlfriend of three months, Tori Spelling, to a table surrounded by Christmas trees. There, the Toronto-bred actor surprised Spelling with a diamond-and-sapphire ring. “It was so magical,” says McDermott. “All the stars aligned.”

The pair seemed more star-crossed when they met in August on the set of an upcoming Lifetime drama: Spelling, 32, had been wed to writer-actor Charlie Shanian, 37, for a year, and McDermott, 39, was in a 12-year marriage to former Canadian TV host Mary Jo Eustace, 44, with whom he has kids Jack, 7, and Lola, 5 months. By September, both were separated from their spouses (their divorces are pending). Why rush back to the altar so soon? “We're so incredibly happy and in love,” the couple said in a statement to PEOPLE. “We cannot wait to start our lives together.” Says McDermott's close pal Michael Olifiers: “I just spoke to Dean, and he said this has been the happiest time of his life. Tori was with him, and she said, ‘Me too!'”