The founder of a Manhattan theater school is a “sexual predator” who preyed on female students, foisting alcohol on them and giving them creepy massages under the guise of vocal training, a new lawsuit alleges.

Andrew Drost, 50, stepped down as head of The Institute for American Musical Theater in December after allegedly being exposed as a “monster” by parents and students, according to the Manhattan Supreme Court suit from last week.

But the accused creep now apparently wants to go back to teaching — prompting the Upper Manhattan institute to take the matter to court in a bid to get him banned from returning.

“He wants to come back and teach the students and he’s not welcome back,” Michael Minarik, Drost’s former business partner at the school, and it current director, told The Post.

The lawsuit details how Drost – who once had a role in “Phantom of the Opera” on Broadway – allegedly put a massage table in the common room, where he would give female students rubdowns, claiming “it was “a method to help relax the vocal cords.”

In another instance, he allegedly used a vibrator to massage a student’s neck — and “insisted it wasn’t anything strange,” the lawsuit says.

The suit also describes a particularly disturbing incident where Drost allegedly plied a 19-year-old female student with booze and fed her what he called an “anti-alcohol pill” before giving her “a full body massage.”

He then continued to sexually harass the young woman, going in for kisses, pressuring her into massages, forcing her to sit on his lap, holding her hand at school and sending her numerous text messages, the suit alleges.

In November 2021 messages obtained by The Post, Drost sent photos of himself – including one of him shirtless – telling the girl that he loved her.

Drost, who’s been a professional ballet dancer, opera singer, Broadway performer and voice coach, is also accused of bullying students and threatening to blacklist them from Broadway if they didn’t do what he wanted, according to the suit.

In addition to allegedly preying on and terrorizing students, the voice coach stole more than $400,000 from the school, which he founded in 2015, the lawsuit claims.

Minarik said students “rejoiced” when they heard the news of Drost’s departure, adding that he received thanks from family and students alike for helping to push him out.

“Once the allegations were told to me the very next day he was gone,” Minarik said. “Because the safety of the students is the most important thing.”

Now, Drost – who agreed to reduce his ownership stake in the school to 25% as a silent partner amid the scandal – is threatening to retake his old administrative role, court documents say.

In his own October lawsuit, Drost claimed Minarik used what he says are bogus allegations to pressure him into a bad exit deal, and said he wants to undo the agreement.

Minarik and the school both filed suits against Drost on Friday opposing his attempt to come back in light of the serious allegations against him and alleged widespread dislike of him.

A judge granted temporary orders from Monday and Tuesday blocking Drost from coming within 500 feet of the school, contacting students or using the school website until a hearing next week.

The school’s suit alleges that on June 4, 2021 in Dallas, Texas, Drost – who was involved with a woman he has since married – plied students with alcohol before asking the 19-year-old woman up to his hotel room where he gave her the pill that made her tired.

Then while she was drunk and drowsy Drost allegedly gave her “a full body massage” making her take off her top and bra before also massaging her upper inner thigh, the suit says.

He then grabbed her to stop her when she tried to leave, and when she was finally able to return to her own room, she threw up, the suit alleges.

Drost “continued to pressure [the student] into massages, to which [the student] acquiesced because she was afraid of the repercussions of saying no,” the suit claims.

Once, when he allegedly tried to kiss her on Dec. 3, 2021, he told her he didn’t know if things would work out with the woman who is now his wife and said, “who knows, maybe you and I will be married in ten years,” the filing claims.

When she rebuffed another one of Drost attempted kisses he said, “That’s strike one,” the suit alleges.

The student filed a report with the police in August 2022, and on Friday a New York Family Court judge issued an order of protection against Drost, according to the suit.

After the allegations came out, Drost told the student to “delete all my text messages” encouraging her to instead move their communications over to Snapchat so that they would disappear after they are read, the suit claims.

When other students tried to “intercede” after they noticed how Drost treated the student, he retaliated by stripping them of “career opportunities, or threatened to do so,” the suit says.

The school claims a slew of other allegedly inappropriate conduct by Drost including that he once spread a rumor that a student had a cocaine addiction, according to the court documents.

Another student developed an eating disorder because he repeatedly told her she needed a “dance body,” the suit claims.

Drost allegedly gave “financial support” to three female students, sending a total of $5,170 to them via Venmo to help with their tuition — “as a method to force the students to remain loyal to him,” the filing alleges.

He also had two female students live with him from 2018 to 2020, with one saying “she felt ‘uncomfortable’ living” there, the lawsuit claims.

The suit accuses Drost of stealing over $435,000 from the school coffers and of often requesting that tuition payments be made to his personal Venmo or Paypal accounts.

“I was completely taken aback and completely ignorant of all of what was happening with him and the students and how he was making them feel,” Minarik told The Post. “And it completely pained me to learn all of this stuff and dealing with the aftermath of it.”

The school is suing Drost for unspecified damages. Minarik is also suing to bar Drost from coming back to the school and to force him to buy himself out of the institution.

Zachary Kuperman, a lawyer for the school and Minarik, told The Post: “We are going to win this suit and we are going to keep him away and the school is going to thrive and the students are going to have a great place to learn musical theater.”

Drost’s lawyer Andres Munoz told The Post: “The two recent lawsuits filed by Michael Minarik distort the truth and are an attempt to completely take over and oust Andrew from the Company that he founded. Mr. Drost is confident that justice will be done.”