A passenger on a budget flight from Manchester to Alicante in Spain was stunned when the couple next to him started having sex on the plane.
According to the Daily Mail, the easyJet passenger was even more outraged when another passenger asked him to move his head so he could get a better view.
Gary Power said two elderly women watched the couple in disbelief.
Power posted his gripe on the airline's Facebook page.
He said: "Well done @easyjet - got on my flight from Manchester to Alicante and what happened during the flight? The man and woman sat next to me proper going for it ... and not even being discreet!
"My particular favourites from the whole experience was that the two elderly women sat opposite, whilst distracting (I presume their about five-year-old granddaughter) so she didn't see it, couldn't get enough of it - eyes popping out of their head with disbelief.
"Oh yeah, and the fella sat in front of them even had the cheek of tell me to move my head so he could get a better look."
The airline responded to Power, asking him to send it a private message. A spokesman for the company said the incident was not reported to airline staff.
The revelation comes amid a spate of lewd and crude behaviour aboard flights from Britain to Spain, which has airline bosses worried.
In June, two Britons were accused of having sex aboard a Ryanair flight to the Spanish resort of Ibiza.
The two people involved in the latest mid-flight romp have not been identified...