What is Jump 'n Hump?
1.
A dance move in which a person will come up behind the dancer or other person and proceed to hump/dance with them until the person turns around, at which time the jump 'n hump individual runs away avoiding recognition and leaving their victim confused and stunned. The literal translation deriving from being physically jumped and then humped.
Girl: (dancing, somehow gets separated from other girls/friends)
Guy: (starts dancing behind her)
Girl: what? (starts to turn around)
Guy: (Turns to girl next to her and starts dancing looking unaware)
Girl: Watch out Meg, there's some guy here doing the Jump 'N Hump.
See
