Flight attendant 'congratulated' the lovebirds after the plane had landed

Passengers had no clue about the sky-high romp until the announcement

Couple allegedly had sex on Norwegian Air flight from Paris to Stockholm

Passengers were left stunned after a Norwegian Air Shuttle flight attendant made an announcement mocking a couple who were allegedly having sex in the plane’s lavatory.

The cabin crew member used the aircraft’s loudspeaker to 'congratulate' the lovebirds who were ‘reproducing’ on the two-hour flight from Paris to Stockholm.

A woman who was on flight DY4314 said passengers cheered and burst into fits of laughter when they learned two of their fellow travellers were joining the mile high club.

A flight attendant offered the crew's 'best wishes of happy reproduction' to the amorous couple (file photo)

She told The Local that the crew member delivered his sarcastic message in Swedish from the cockpit after the Boeing 737-800 landed in Sweden’s capital on Monday night.

The woman added: ‘He said something like “We’d like to send our best wishes of happy reproduction to the couple that ventured into the toilet earlier on”.

‘People around the plane started cheering and laughing and there was a lot of gossiping about who it could have been.’

It’s not known where the amorous couple is from or how the crew learned of their romp at 35,000ft.

A spokesperson for Norwegian told MailOnline Travel: 'We can confirm there was an incident on board a recent flight from Paris to Stockholm involving two passengers.

'Whilst we appreciate that Paris is the city of love, we expect passengers to refrain from this type of behaviour on board.'

The spokesperson said police were not contacted as flight safety wasn't compromised.

The pair had a sky-high tryst as Norwegian Air Shuttle flight DY4314 was on its way from Paris to Stockholm

While it may seem humorous, sky-high sexual trysts on board commercial jets have been no laughing matter in past incidents.

A number of couples have been charged in recent years for engaging in sex acts in the lavatory and in their seats, including a Canadian pair who was spared jail time.

Earlier this year, Alicia Elizabeth Lander, 26, received a six-month conditional sentence and nine months of probation over an incident on board an Air Canada flight in January 2014.

Court was told she and Jason George Chase downed several shots before the flight and were caught fondling each other under a coat.

Police met the plane when it landed at the airport in Halifax, Nova Scotia, and the pair was arrested.

Mr Chase was given 18 months of probation and a conditional discharge.