Things got too hot in the steam room of one Manhattan gym, a lawsuit claims, after three men fixed their gazes upon an unwitting visitor, dropped their towels and started pleasuring themselves.

“I’m relaxing, I’m sitting in the corner, it’s very meditative,” the alleged victim said of the initial vibe during a quick lunchtime steam at the Equinox gym on Broadway in Gramercy Park.

“The steam clears . . . And I look across from me. This gentleman, sitting pretty close, his towel is open, his legs are spread and he’s looking right at me, and the guy next to him was rubbing [the man’s] inner thigh,” the victim told The Post.

“He’s looking right at me, his towel’s off and he’s masturbating,” the victim said.

The out-of-place gym-goer really began to sweat when he realized a third man in the tiny space was also staring at him and masturbating.

“I thought, ‘No escape, I’m going to be sexually assaulted,’” just before fleeing, he recalled.

The freaked-out man told the front desk, but nobody took any action, the man, identified only as GB in court papers, alleges.

Equinox “had known for as much as 10 years prior that similar wrongful acts were occurring in its steam showers,” he alleged in a Manhattan Supreme Court filing against the fitness chain.

“It is a problem, and it’s something that every gym in New York City, not just Equinox, has an issue with,” the manager said in a conversation with the victim, a recording of which was obtained by The Post.

The November incident left the straight, single dad “shaken up,” he said.

The gym “thoroughly investigates” complaints “and did exactly that in this case,” a spokeswoman said., adding, “We maintain a zero-tolerance policy for any inappropriate behavior in our clubs.”

But the gym allegedly refused to revoke the offender’s membership, said GB’s lawyer, Marc Held.