It’s open season on men at Columbia University thanks to the Ivy League school’s handling of sexual-harassment allegations against male students, a new lawsuit charges.

Expelled Columbia student Ben Feibleman says he fell victim to “anti-male, female protectionists’ gender biases permeating Columbia’s disciplinary process’’ after a female pal in 2016 accused him of rape.

The young woman had allegedly begged him for sex one night that October before forcing him to fool around, ­alleges Feibleman, who filed a lawsuit Tuesday in Manhattan federal court.

The woman told her friends in the days that followed that Feibleman sexually assaulted her and she reported the incident to faculty about a week later, the suit says, but not to police.

Columbia investigated the matter and obtained an audio recording of the alleged rape, as well as photos from the pair’s evening together before they went to her room.

Feibleman says he and the woman struck up an “hours-long flirtation” that night after meeting up at a reception. He alleges in the complaint that they took a trip to a water tower on top of an apartment building, where the two kissed and the female student pulled Feibleman’s face into her breasts.

They allegedly ended up alone in the woman’s room, where Feibleman claims there was consensual kissing and fondling. It is here when the woman allegedly begins to beg Feibleman for sex, his suit says, but he refused — citing the fact that the woman was seeing another man.

The refusal didn’t sit well, according to the suit, and the female allegedly berated Feibleman for half an hour.

“Please because I can’t let you go without it,” she begged, according to the suit, which accuses the woman of trying to perform oral sex on Feibleman, as well as biting him.

“Ben simply did not want to have sexual intercourse with [the woman],” the suit states.

The suit says Feibleman eventually started thinking he might be accused of misconduct, so he made a 30-minute phone recording of his encounter in the woman’s room.

The recording, however, was unable to convince Columbia investigators that he was innocent. The school found that his female friend was too drunk to consent to any sexual relations and deemed Feibleman — who graduated from Columbia’s Graduate School of Journalism — responsible for sexually assaulting her. He was expelled and his degree is currently being withheld.

Columbia declined to comment and woman did not respond to requests for comment.

Feibleman’s suit mentions “Mattress Girl’’ student Emma Sulkowicz, who in 2014 famously carried a mattress around Columbia’s campus to protest against the school for taking it easy on her alleged rapist, who sued the school and reached a settlement.

Feibleman referred questions to his lawyer, Kimberly Lau, who issued a written statement stating the university “grievously mishandled this case.”