A Jet2 flight from Stansted to Gran Canaria was diverted to Portugal after a couple started arguing in mid-air, a court heard.
The Boeing 737, flying to Las Palmas, was diverted to Faro on July 6 last year.
Ronald St Ville, 53, and Pauline Gordon, 66, both of Stratford, London, were charged with endangering the safety of an aircraft.
The couple denied the charges at Chelmsford Crown Court, the BBC reported.
Prosecutor Peter Gair said the pair were flying together when an expletive-riddled argument started over a text message.
A fellow passenger told the jury he heard the couple arguing and swearing intermittently for more than an hour and thought they were drunk.
The witness, a former policeman, said St Ville had threatened to hit Gordon in what he described as an “argument between a domestic couple”.
Cabin crew and pilot made the decision to land the aircraft in Portugal and remove the couple after separating them, the court heard.
The trial continues.