Liev Schreiber cheers son on at dance convention in Hauppauge

"Ray Donovan" star Liev Schreiber was on hand in Hauppauge Sunday as his and actress Naomi Watts' 10-year-old son Kai attended a Turn It Up Dance Convention.

"Kai turning it up at the Turn it up convention!" wrote Schreiber, 52, on social media. He also posted a video of Kai at the Radisson Hotel’s ballroom, dancing with a group of other youngsters in a choreographed routine set to a percussive song. He wears the same long blond hairstyle as in a video his mother posted in June showing Kai and Liev Schreiber dancing to Queen's "Another One Bites the Dust," but in a ponytail at the con.

"Kai crushed it today at the Turn It Up Dance Convention," Watts, 51, similarly posted on Instagram, with a black-and-white photo of Kai and other kids on the ballroom floor having snacks together. "The Loudest Voice" actress tagged the TriBeCa dance school Downtown Dance Factory, which itself posted Instagram photos of some of its students at the event.

Among those offering supportive comments at Schreiber's Instagram feed was producer-comedian Mindy Kaling, who wrote "This is awesome." Cookbook author Jessica Seinfeld — wife of comic Jerry Seinfeld, whose homes include an East Hampton mansion — put up a heart emoji on Watts' Instagram comments. Elle Fanning, who played Watts' transgender daughter in the film drama "3 Generations," also liked the post.

"One of the other studio directors came up to me and said, 'The Ray Donovan is here,' " said Joelle Bellmund, client relations director for the Weymouth, Massachusetts-based Turn It Up Dance Challenge. She was referring to Schreiber's character on the Showtime crime drama that began its seventh season Sunday.

The convention had not been aware that Schreiber would be attending. "We obviously know the dancers' names but not necessarily who their parents are," Bellmund said. While she did not speak with Schreiber, "I was standing next to him while we took a group photo of the room; his son was with him. His son actually won a scholarship.” Additionally, the actor "bought something from our merchandise table."

Attendance at Turn It Up conventions is “female-heavy, but we had quite a few boys at this event in particular," said Bellmund, "and I think three of them received scholarships" to future conventions and to a three-week course to perform with the group that opens for the company's national dance team.

Schreiber and Watts, who broke up in 2016 after 11 years together, are also parents to son Sasha, 12.

Through their representatives, the actors had no additional comments.