Robert F. Kennedy Jr. seems to be inseparable from actress Cheryl Hines, famous for playing Larry David‘s wife on HBO’s “Curb Your Enthusiasm” — sparking rumors they are a couple.

The environmentalist son of Bobby Kennedy and nephew of JFK was spotted constantly at the side of the blond actress/director at the premiere of the documentary “The Last Mountain” Wednesday night.

The couple, who both filed for divorce last year, were seen cozying up at the Rouge Tomate after-party but seemed shy about being photographed together.

A spy said, “They arrived together. He hugged her and had his hand on her back at one point and kept introducing her to people. He was by her side all night.”

In the film, Kennedy helps Appalachian families defend their community after a coal-mining giant proposes to gouge into a mountain.

The night before, Kennedy was with Hines at the Royalton for the HBO doc “Bobby Fischer Against the World.” They were also seen posing for pictures together in Aspen in January and were reportedly on the slopes together in Deer Valley, Utah, in December. Meanwhile, we’ve reported that Hines has been helping his actress daughter, Kick Kennedy, with Hollywood introductions.

Hines’ rep said, “Cheryl and Robert are friends who support each other’s projects. Cheryl attended the premiere to lend support to a very important cause.”

Kennedy’s aide didn’t return calls.

Hines and her husband of seven years, Paul Young, announced they were divorcing last July. Kennedy filed for divorce from his wife of 16 years, Mary Richardson, last May.