While attending the Marjorie Prime premiere after party at the Acura Studio on Monday night at the Sundance Film Festival, the actor — who split from longtime girlfriend Diane Kruger last summer — was spotted hitting it off with a mystery brunette.
According to a partygoer, the 38-year-old star of Showtime’s The Affair arrived solo at the bash and was in high spirits, drinking cocktails and dancing along to a Justin Timberlake song before getting close with the woman, who wore a floor-length orange dress.
“He was having a blast and at one point got really cozy with her,” says the onlooker. “They were dancing, and he really looked like he was having fun just living the single life.”
The duo continued partying at the Beatriz at Dinner after party at Chase Sapphire on Main. “They were making out at the bar for a good 45 minutes,” says an onlooker.
In December, Jackson opened up to Ellen DeGeneres on her show about navigating the dating world after his breakup.
“Things have changed a little bit since the last time I was single — maybe it was there, but I don’t remember all of [it],” he said. “I mean, everything in your phone now, right? There’s no more talking to people anymore! It’s been quite a big change.”
This article originally appeared on PEOPLE.com.