The alleged love child of Frank Sinatra and Mia Farrow handled the startling news his way — with humor.

“Listen, we’re all *possibly* Frank Sinatra’s son,” handsome, blue-eyed lawyer, journalist and human-rights activist Ronan Farrow tweeted Wednesday.

Ronan, long described as the only biological kid of Mia Farrow and filmmaker Woody Allen, yukked it up after his mom admitted in Vanity Fair magazine that Sinatra was “possibly” his real dad.

Mia Farrow was married to Sinatra for two years between 1966 and 1968, and they remained lovers even after their split.

Ol’ Blue Eyes, who passed away in 1998, would have been about 71 if he fathered Ronan in early 1987. Ronan was born in December of that year.

Meanwhile, the one-time Rhodes scholar, 25, is in negotiations for a hosting job on MSNBC, sources told The Hollywood Reporter. A MSNBC rep could not be immediately reached for comment.

Mia Farrow declined to comment at the family’s Connecticut estate, and a worker on the grounds said Ronan Farrow would also refuse to speak.

The Yale Law School grad has served in the Obama administration’s State Department. He also has teamed with his mom on various human-rights projects over the years.

Ronan Farrow said working side-by-side with his famous mom isn’t easy, but it’s always rewarding.

“It’s an unusual thing to do with one’s mother, and very often we disagree, but I love working with her,” he said.

The Vanity Fair piece shed new light on 20-year-old allegations against Allen, who was once accused of molesting Farrow’s then-7-year-old daughter Dylan.

Authorities in Connecticut declined to press charges against Allen in 1993, although the lead prosecutor said he had enough evidence to go after the legendary writer-director.

New York City child-welfare investigator also looked into Dylan’s allegations. Even though the alleged crime happened in another state, New York authorities wanted their own probe in case Allen was ever accused of wrongdoing here.

Ronan Farrow (left) with his mother Mia last year.StarTraks

New York investigator Paul Williams reportedly found Dylan’s claims to be credible, but that case file has mysteriously vanished from child-welfare archives, sources told Vanity Fair.

That report could have prevented Allen’s adoption of two baby girls in 1999 and 2000 with wife Soon-Yi, Mia’s daughter.

Dylan claimed that Allen told her to keep the alleged abuse quiet. “He said, ‘You can’t tell anyone.’ I didn’t realize how careful he was,” she told Vanity Fair. “I was not feeling OK with him putting his thumb in my mouth or how he hugged me.”