John F. Kennedy Jr. would be “embarrassed” by his nephew Jack Schlossberg’s recent social media antics, according to sources.

Schlossberg — whose resemblance to his uncle is unmistakable — has spent the past few days raging against independent presidential candidate Robert F. Kennedy Jr., his own cousin.

The only grandson of President John F. Kennedy has posted a series of bizarre videos on Instagram in which he plays characters with different accents, from a cockney Brit to a New York Jew.

Calling himself Jimmy and speaking in a thick Boston brogue, he calls RFK Jr. “a prick” in one video.

“I think John would be embarrassed,” one source who knew JFK Jr. well told The Post. “This is his nephew … Jack and John would be very close if John was here.”

In a series of Instagram posts, Schlossberg, 31, has suggested that RFK Jr. is using steroids, and “lying to us,” as well as claiming that the candidate is a Russian patsy.

He also stripped off his shirt and crooned the Beatles’ “Ticket To Ride” while pouting at the camera.

“When Jack is singing, he looks so much like John that it freaked me out a little,” the JFK Jr. source admitted.

Schlossberg also portrays Joshua, an older New York Jewish man who fears that RFK Jr. will do away with the Federal Reserve, shouting, “Who is going to protect my money?”

Another Kennedy source admitted that no one else in the family has a clue what Schlossberg is doing.

“No one knows where Jack is going with this. It’s crazy,” the Kennedy source said. “I think John Jr. would have talked to him.”

Rory Kennedy, a sister of RFK Jr., is publicly against her brother’s presidential bid. When asked by The Post if she supported Schlossberg’s videos, she dodged the question.

“The stakes of this election couldn’t be higher. Donald Trump has said he’s running to be a dictator on day one, and he is running a campaign on fear, revenge and retribution,” she said.

Schlossberg, 31, a Yale graduate who also attended Harvard Law School, passed the New York state bar exam in April 2023, but does not appear to have a full-time job.

His mother, Caroline, is the US ambassador to Australia. Schlossberg is RFK Jr.’s first cousin once removed.

Schlossberg, whose father is Caroline’s husband, art collector Edwin Schlossberg, has increasingly taken a public role with the family’s Profile in Courage Awards and with various political and philanthropic causes, including speaking at the 2020 Democratic National Convention.

He once worked as a Senate page and intern and for former Secretary of State John Kerry — who has said of him: “A sense of humor is not genetic, but apparently in the Kennedy family it can be inherited. In President Kennedy’s grandson, Jack Schlossberg, this quality seems to abide.”

We have reached out to Schlossberg and Caroline Kennedy for comment.