Everyone knows that famous flight scene in Bridemaids where Kristen Wiig's character has a few too many shandies.
It's easily done when you're cramped in a small space for many hours, with limited options to keep you entertained.
An anonymous American Airlines flight attendant has revealed how cabin crew keep in-flight boozing under control.
"When you think about it, being on board an aircraft is really one of the only situations in which it's vaguely socially acceptable to day-drink by yourself," she told MailOnline Travel.
"The majority of passengers who drink will have two. One when service commences and another one with a meal. Then there are always the ones who can knock back four. It's easy to overdo it."