Can you figure this out?

I forgot the name of a song of an electronic pop music video I watched a couple years ago.

It starts off with a guy very bored at a party and he notices a girl. He has a few drinks then goes to the other room to lay down, when the girl he noticed earlier appears infront of him. He seems to be hallucinating her but she dances around him and in the end of the video it ends with him holding her necklace. I think the shape was a triangle or something.

Anybody have ideas?