The guy who got caught vaping in the lavatory on an American Airlines flight followed through with his threats to file a police report against the flight attendant … and he told cops she exposed his genitals and assaulted him.

TMZ obtained the report Peter Nguyen Wong filed with police in California … and he claims the flight attendant unlocked the lavatory door while he was inside and caught him taking one hit from a vape.

When the flight attendant allegedly opened the door, Wong claims his genitals were exposed to other passengers.

What’s more, Wong says when he tried to board another flight the next day, an employee told him he had to delete the videos before they would allow him to board.

Wong also told cops he’s gotten several messages and phone calls since the incident went viral … he claimed some of the alleged messages contained vulgar and aggressive language and said he was concerned for his safety.

The police report says Wong wants the flight attendant prosecuted for assault.

Wong was flying from Phoenix to San Francisco when he got caught vaping … and cops were waiting to talk to him when the plane landed in SF. Vaping is banned by the Federal Aviation Administration aboard commercial flights along with all other types of smoking. He says cops released him after speaking with him.

He filed the police report in Redlands, CA, about a week after the incident … and cops in Redlands tell us they will forward the report to the San Francisco Police Department.

It will be interesting to see if SFPD opens an investigation and if the flight attendant is ultimately prosecuted.