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

Watch: Haim and Taylor Swift perform 'Gasoline' and 'Love Story' mash-up together in London.

| by Shahlin Graves

Haim brought out Taylor Swift as a special guest at their sold-out show at London's O2 Arena tonight, performing a mash-up of 'Gasoline' and 'Love Story' onstage together.

Watch fan-filmed videos of the performance below...