Anthony Weiner shared his lust for underage girls during a series of raunchy sexting sessions with a woman who could pass for a teen, she told The Post on Friday.

“I told him I was 30 to 31 years old, but he didn’t want to hear that — he said I looked like a little girl and that turned him on,” the woman said.

The woman — a petite, busty blonde who lives in the Midwest — said she reached out to Weiner through Facebook in the fall of 2015. They communicated online for about eight months, she said.

During one sexting session, the woman sent Weiner a video clip of herself masturbating.

He wrote back, “You’ve got a little girl p—y. Tight as f–k. Punish you.’’

Weiner also shared a fantasy of “throwing you over my knees” for a spanking — but had to cut short a discussion about “this hard-on you keep giving me” when he was interrupted by his 4-year-old son.

“Sorry baby. My son wanted to cuddle. Had to put down my phone,” he explained.

Smartphone screengrabs reviewed by The Post show Weiner was sexting with the woman around the same time he reportedly exchanged lewd messages with a 15-year-old girl in North Carolina.

That relationship now has the disgraced ex-pol under investigation by the NYPD and the FBI.

The Midwestern woman has been busted for drug possession and has a drinking problem.

Weiner could not be reached.