A video (normally captured on a mobile phone) of one or more people doing something forbidden or disgusting in an airplane toilet. This term usually suggests something more than 'the mile-high club' and often involves close-ups of faeces or ejaculate being sucked away by the powerful vacuum of the airplane toilet bowl. The 'build-up' to said acts may or may not be recorded.

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy