Justin Bieber -- Tatted Up at 40,000 Feet

Justin Bieber has joined a very exclusive mile-high club that does not involving banging ... but it does involve body parts and a little prick.

It's true ... TMZ has learned Bieber got fresh ink on a flight to Canada just five days after his infamous Miami Beach arrest. The new tat was done by New York City tattoo artist Bang Bang, who has tatted up the likes of Rihanna, Selena Gomez, Katy Perry and many other big celebs.

Bang Bang tells TMZ the work was done at 40,000 feet (which he thinks might be a record for highest altitude tattoo) and during terrible turbulence. He called it "the most difficult tattoo I’ve ever done for sure."

In case you're wondering ... a rep for the FAA tells TMZ there is nothing illegal about getting a tattoo aboard a plane, as long as it doesn't interfere with the safety of passengers and crew.

As for the significance of the tattoos ... Bang Bang says Bieber sent him a text afterward, explaining, "Forgiveness is powerful, forgive as Jesus died on the cross to forgive our sins."

Or strike a plea bargain. Whichever works best.