“More and more people are now travelling by air so it’s no surprise that flights have become a place to flirt. After all, you are sitting next to someone for an hour or more, and the fact that you’re both travelling to the same place means you already have something in common, Karin Noble an employee from Skyscanner and a former cabin crew member.  

Add this to the heightened effect that alcohol can have at altitude and the more relaxed ‘holiday mood’ that many travelers feel, and it tends to give people the courage to flirt with a fellow passenger or even take things further, especially on long haul routes such as flights to Australia.”  

More shockingly, for a small minority the flirtations may actually lead to membership of the infamous Mile High Club. The Mile High Club (or MHC) is a slang term applied collectively to individuals who have sex while on board an aircraft in flight. There is no known formally constituted club so named. However, since "membership" of the "club" is really a matter of an individual asserting they have qualified, the qualifications for membership are open to some interpretation.  

One explanation for the club's allure is the vibration of the plane, which may make arousal easier. Others say they have fantasies about pilots or flight attendants, or a fetish about planes themselves. For many others, perhaps the majority, the appeal of joining the MHC is the thrill of doing something taboo and the thrill of the risk of being discovered.