Anthony Weiner spent months sexting with an underage girl he tried to lure into “rape fantasies,” it was revealed Wednesday — and the ex-pol’s new low could send him to the slammer.

The 15-year-old high school student went public with a trove of lurid come-ons she got from Weiner, who exchanged his “Carlos Danger” persona for the alias “T Dog” to send her kinky texts and shirtless selfies over a cellphone messenger app.

Weiner repeatedly told the unidentified teen how “hard” and horny he was, at one point boasting that after sex with him, she would “limp for a week,” the Daily Mail reported.

Weiner — whose serial sexting cost him his seat in Congress and a comeback bid for mayor — also shared pornographic videos with her, asked her to get naked and masturbate for him over Skype, and even told her about “rape fantasies” that grossed her out.

“It would just be him showing up at my house when my dad was out of town,” the girl told the Mail.

Gov. Andrew Cuomo reacted with disgust, saying that “if the reports are true, it’s possibly criminal and it is sick.

“And frankly, I’ve heard enough about Anthony Weiner and I think that goes for all New Yorkers,” he added.

Legal experts said Weiner could be exposed to a slew of state and federal charges — including one that carries a mandatory minimum of 15 years in prison.

“The federal government is very strict — not that state isn’t — but the feds are very strict when it comes to sex offenses involving children,” defense lawyer Renee Hill said.

“He could be in some really serious trouble here.”

The girl told the Mail she began exchanging messages with Weiner in January and continued through July.

She decided to blow the whistle after seeing the lewd selfie The Post published last month, showing Weiner aroused in his undies while lying in bed next to his then-3-year-old son.

That exposé led Weiner’s long-suffering wife, top Hillary Clinton aide Huma Abedin, to finally announce she was ending their marriage.

It also prompted a probe by the Administration for Children’s Services that remains open, sources said.

Weiner’s underage sexting partner said she didn’t want to press charges because she believed what they did was consensual — but experts said her testimony wasn’t needed.

Defense lawyer Andrew Stengel, a former Manhattan prosecutor, said Weiner could get slapped with disseminating indecent material to a minor and promoting the sexual performance of a child.

Each crime carries up to seven years behind bars, and a conviction for dissemination would force Weiner to register as a sex offender.

On the federal level, Weiner could be charged with sexual exploitation of children, which carries a minimum of 15 years in prison and a maximum of 30.

Spokesmen for Manhattan DA Cyrus Vance and Manhattan US Attorney Preet Bharara declined to comment.

The girl’s father, whom she identified as a lawyer in her exchanges with Weiner, told the Mail that he “couldn’t stomach” what Weiner had done to his daughter, who’s been treated for depression.

The girl said Weiner tried to cover up the sexual nature of their relationship by pressuring her to write a letter to her father and a teacher in whom she had confided “and tell them what I said was false.”

In a desperate bid to defend himself, Weiner gave The Post a full version of the letter, which included the girl’s name and the names of two teachers — information that suggests she lives in North Carolina.

In a prepared statement, Weiner said the letter showed “that I have likely been the subject of a hoax” — but he didn’t deny any of the girl’s claims.

“I have repeatedly demonstrated terrible judgement [sic] about the people I have communicated with online and the things I have sent,” Weiner wrote.

“I am filled with regret and heartbroken for those I have hurt…. I have no one to blame but me for putting myself in this position. I am sorry.”

Additional reporting by Rebecca Rosenberg and Larry Celona