Psy and Snoop are party pals in new 'Hangover' video

Instant hit?

Looks like it - if nearly 4 million YouTube views overnight is any indication. Psy and Snoop Dogg are skipping, dancing, doing shots together -  and complaining about how they feel the next morning - in this new video.

Last month, the Gangnam Style singer told TMZ he and Snoop partied off-camera during the filming of the music video in South Korea. "We were Hangover," Psy said.