Three young Irish lads were the talk of Twitter after the Rose of Tralee finale on Tuesday night.
RTE had called on viewers to tweet pictures of themselves watching the event at home.
MC for the night Will Leahy read out some tweets and showed pictures of fans as the showed neared its end.
But the unsuspecting presenter didn't notice a prank pulled off by Kieran Byrne and some of his pals at home.
He uploaded what appeared to be an innocent photo of them watching the competition with the "World Irish Dancing trophy".
He said: "Enjoying the Rose Of Tralee 2019 with the World Irish Dancing trophy. #Roseoftralee ."
But eagle-eyed viewers found there was more to it than meets the eye, after noticing another friend mooning the camera in the window's reflection.
To Will Leahy's credit, he acknowledged the fast one pulled by the youngsters after the picture was broadcast live on RTE One.
He tweeted: "Well done to these lads. After their picture was on telly, eagle-eyed viewers spotted the mooner - Top left corner."
The joke went down a treat with Twitter users, with many uploaded a screenshot of the person displaying their bare backside.
It came as Limerick Rose Sinead Flanagan won on what was the event's 60th anniversary year.
The junior doctor, from Mungret and lives in Adare, said she’s proud to be representing her county and that participating was a "prize in itself".
