What music video is this?!?

I can remember part of the music video for this song, but not the song itself! The video starts off with a tall, skinny hipster kid in blue shorts and a white tank turning on a boombox and dancing in front of a mirrored wall awkwardly. And later on I vaguely remember people dancing in a drained, in ground pool. I don't think the song is much more than two years old. Any idea what video/song I'm thinking of?