Drunk passengers are the worst type of flyers, according to some flight attendants.
Whether being unruly after consuming too much alcohol on the flight or bringing their own booze on-board, cabin crew have revealed the worst offenders.
SEE ALSO: Two bottles of wine broken on first-class passenger's head
SEE ALSO: Ryanair bans duty-free alcohol on UK flights to Ibiza
One anonymous flight attendant working for an American airline told MailOnline Travel: "We are trained to monitor people using a traffic light system.
"If you're exhibiting 'green' behaviours then we're fine to serve you, if you're moving into 'yellow' territory then it's time to slow down, and as soon as you enter 'red', we cut you off."
She added that 'red' behaviours include spilling things and slurring and "it's a red flag if someone is getting up to use the lavatory more often than normal."
Meanwhile, the number of passengers being arrested for drunken behaviour on British flights is on the rise, with a total of 387 held in the last 12 months - up 50 per cent on the previous year, according to BBC's Panorama.
Cabin crew told the programme that they found "countless litre bottles of vodka" on planes, as well as Jägermeister and Bacardi.
They revealed that the worst routes for drunken behaviour were Alicante, Ibiza and Palma.
It comes as the Home Office is "considering" calls for tougher rules on alcohol at UK airports and budget airline Ryanair called for a crackdown.
The airline wants to ban early morning sales of alcohol in bars and restaurants, and limiting the number of drinks sold per boarding pass.
But if you thought the worst behaviour was found on budget airlines you were wrong as we've rounded up the best of bad-behaving first-class passengers...