The low-key lovebirds cuddle – and make out – at a screening and party for their new film

By Paul Chi and Jeffrey Slonim
Updated October 16, 2008 08:20 AM

After months of low-key dating, it seems Michelle Williams and Spike Jonze are finally ready to take their romance public.

After attending a Cinema Society screening of their new film, Synecdoche, New York in Manhattan Wednesday night, the couple walked out of the auditorium with Jonze caressing Williams’ back and wrapping his arm around her waist.

The pair held hands as they walked through the lobby, where they met up with Synecdoche costar Catherine Keener. While the two women chatted and munched on popcorn, Jonze snaked his arm around Williams’ waist again.

“He couldn’t seem to keep his hands off her,” said an onlooker. “It was very cute.”

But the sparks really started to fly later that night, when they headed to the Gramercy Hotel’s rooftop club for the Mulberry-sponsored afterparty.

While the two – who have been romantically linked since this summer – talked with friends, they stood so close they were “practically spooning,” said one fellow guest.

And later, when they decided to leave the bash at around 1 a.m., Williams and Jonze shared a mini makeout session – on their way to the elevator.

Williams, 28 – who has an almost-three-year old daughter, Matilda, with the late Heath Ledger – met the director in 2006, when she audtioned for his film, Where the Wild Things Are. They reconnected last year, when she signed on to star in Synecdoche, which he produced.