Travellers on the flight to Stockholm were left giggling after a member of the flight crew offered a special message to two passengers who had apparently been caught doing a lot more than French kissing during the journey.
The air steward delivered his message in Swedish from the cockpit after the plane landed in Stockholm.
"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'," a Swedish passenger who was on the Norwegian airline flight told The Local.
The woman, who wished to remain anonymous, added: "People around the plane started cheering and laughing and there was a lot of gossiping about who it could have been".
The crew member shared his jokey message of congratulations on the D4314 fight to Stockholm on Monday night, which left Paris at 21:15. But he gave no further details about the apparent mile-high antics of the couple.
Passengers who did not speak Swedish were left baffled by the message, with the steward merely saying "Welcome to Sweden" in English over the tannoy.
The nationality of the couple caught romping remains uncertain, as does exactly how the flight crew found out about their mile-high antics.
While earlier reports suggested that the person who made the announcement on the plane was the aircraft's pilot, a press spokesperson for Norwegian confirmed to The Local on Wednesday that it had in fact been a member of the cabin crew.
The company declined to comment further on the incident.