Flight attendants can open the toilet doors from the outside to interrupt frisky couples who romp in the lavatory during a trip.

While flying abroad, Catriona Harvey-Jenner queried whether many couples actually “join” the mile high club and was shocked when a British Airways host confirmed they do.

Harvey-Jenner took to Reddit to uncover how flight attendants interrupt people having sex on the plane and revealed her findings in an article for Cosmopolitan.

A Reddit user commented: “I dated a Flight Attendant for a while.

“She said that what they would sometimes do is just unlock the door from the outside and walk away.

“The couple would then often knock the door open mid-coitus and fall out.”

One airline worker rounded up other passengers to publicly shame a couple: “On a flight to Switzerland a couple of years ago, there was a couple who ‘mile-high clubbed’ a couple of times over the course of the flight.

“The final time was right before breakfast was being served, and the flight attendant had everyone on the plane give them a round of applause for being the most consistent passengers she had ever seen.”

Another person, who claims to work on ground crews at airports, said it is “not unknown to find crew members s******g in the bathroom between flights.”

Another flight attendant caught a pair trying to “get down” in the galley.

She wrote: “I had a couple ask if they could stand in the galley for a few minutes to stretch their legs.

“They were very polite, and I said sure and went back to reading my book.

“I made it halfway down the page, when I heard her moaning, and I turned and looked and the guy had her pinned up against my coffee makers with his hand up her shirt.

“I promptly told them to remove themselves from the galley and either finish up in the lav, or head back to their seats and keep their hands to themselves.

“If I can’t get it on in my galley, no one can get it on in my galley.”

Allegedly, certain members of the NYPD accepted private plane rides featuring tickets to the mile high club: