Metro

Boss: rat’s my boy

In the world of the Mafia, it’s never come to this.

Yesterday in a Brooklyn federal courtroom, legendary Colombo underboss John “Sonny” Franzese, 93, sat stoically while his son ratted him out for his life of crime.

Asked to finger his once-feared father in court, John Franzese Jr. — a former wiseguy-turned-FBI informant — said only, “He’s sitting there in the yellow shirt.”

Father and son barely exchanged glances, but the elder Franzese pinched the fabric of his shirt, as if to question if he was the guy being called out by his son.

Franzese Jr. made history yesterday. No other big-time mobster’s son had ever testified against his father.

But Franzese Jr., 50, wearing a cross around his neck, a green T-shirt and jeans, testified about how his father — once was so feared that Frank Sinatra reportedly kissed his ring in public — introduced his son at age 16 to a life of crime.

Franzese Sr. is standing trial on charges of shaking down a pair of strip clubs and a pizzeria on Long Island.

The younger Franzese recalled becoming a Colombo bagman by 18, with all the trappings and riches that came from being connected to a powerful mobster.

But he testified that he eventually descended into drug addiction, and to turn his life around he decided to begin informing for the FBI.

“I wanted to change my life,” Franzese Jr. said from the witness stand. “They would provide a means for me to change my life.”

As a tape that Franzese Jr. made while wearing an FBI wire was played in court, his father appeared to doze off, prompting his lawyer to nudge him awake.

The tape recording, in which a Franzese cousin was heard predicting that John “Junior” Gotti would end up ratting out his father rather than sit in jail — was made while the younger Franzese was the real family rat, wearing a wire to help capture his own dad.

The son’s testimony horrified his brother, Michael Franzese, a former made member of the Colombo crime family who became a born-again Christian. He said the family is crushed by his brother’s betrayal.

“I don’t agree with anything he’s doing,” said Michael. “The family is taking it very hard.”

But his mother was more understanding.

After her son took the stand, Cristina Capobianco said John Jr. testified simply as a way to reject the mob lifestyle that his father had brought him up to lead.

“He never had a life,” Capobianco said. “He’s a compassionate person. He just doesn’t want this life anymore. He’s not made for this — he never was.”

Capobianco insisted that her son told her, “I’m not testifying against Dad. I’m testifying against a lifestyle.”

janon.fisher@nypost.com