When you're playing Worms World Party and somebody presses the spacebar during your turn and makes you fuck up and hurt yourself.

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

To apply your fingers to a womans nether regions in a fashion similar to that of using a spacebar on your computer keyboard.