An acting student was caught in a real-life drama when his so-called “f–k buddy” accused him of rape and got him kicked out of his posh performing-arts school, according to a suit.

The American Musical and Dramatic Academy quickly expelled the alleged assailant in January, after the classmate said she didn’t feel safe at the Manhattan campus and told a teary tale of how the teen had forced himself on her in a dorm room.

But instead of doing a thorough investigation, administrators made a “rush to judgment” and bought the young woman’s claims hook, line and sinker, the alleged assailant gripes in a Manhattan Supreme Court lawsuit accusing the school of “anti-male” bias.

The Post is withholding the names of both students involved in the case.

“The absence of any real investigation and the speed in which the committee reached its decision reveals the school’s anti-male bias and rush to judgment,” he said in court papers.

The alleged assailant said he’s too scrawny to have sexually assaulted the young woman.

The alleged assailant “is 110 pounds and extremely thin. [The alleged victim] is significantly larger . . . and she could have easily overpowered him or left her room if [the assailant] was making unwanted sexual advances,” says the lawsuit.

The two were longtime friends and “ ‘f–k buddies’ and had sex on two or three prior occasions,” the male student told the school. He admitted he’d talked the young woman into sex by telling her things wouldn’t work out with her boyfriend.

“I would have never done anything if I thought she didn’t want to,” the alleged assailant said he told school officials. “I asked her, ‘Are you OK with this?’ and she said, ‘It’s OK.’ ”

The young woman claimed the two were not close, only that her mom was the alleged assailant’s high-school voice coach, the court papers say.

The school, whose alums include actors Tyne Daly, Paul Sorvino and Jesse Tyler Ferguson, refused to look at text and online messages between the two proving their friendship, the young man claimed.

The young woman “took pleasure in everything [he] did physically,” the suit said.

No one called the cops, and there was no physical evidence; a committee assigned to investigate the case didn’t interview either student, the suit charges.

The committee “immediately credited” the woman’s version of events, “adopted the anti-male based narrative… and twisted [the alleged assailant’s] words to suit their own purposes and support their decision.”

The student’s expulsion was later modified to a suspension through the summer. He wants the expulsion overturned and all references to the allegations expunged. The young woman and the school did not return messages.

Additional reporting by Caroll Alvaradoand ­Jennifer Bain