coup de main - noun
kü-də-ˈmaⁿ
Definition of coup de main : an attack that achieves complete surprise.

One Direction's Liam Payne dancing to 'Gangnam Style'.

One Direction fans voted for Liam Payne to dance along to Psy's 'Gangnam Style' during a recent interview for The BBC's Radio 1.

Watch Liam dancing below...