Flex is a bizarre short film by Chris Cunningham, a director famous for his work making music videos with Madonna, Björk and Aphex Twin. It was commisioned by Anthony d'Offay for his gallery, and its main run was at the controversial Apocalpypse exhibition at the Royal Academy of Arts in London. Its soundtrack is by Aphex Twin, and it is currently running at the Edinburgh College of Art along with the Monkey Drummer film as part of the Edinburgh Festival from 10am-5pm every day until 26 August 2001. I would recommend seeing it; it's one of the few free things at the festival, and seems likely to never be released to the public in recorded form.
The film consists of a couple alternately having sex - not simulated, real sex - and then savagely beating each other. This occurs against a perfectly black backdrop, and while they copulate they seem to float in starless space, while a solid beam of intensely bright liquid light shines on them. The fight is incredibly vicious, shot as a fast montage, and combined with the twisted beats of Aphex Twin's aural assault it is an incredible sensory and emotional overload, as the woman is left in a bloody pulp by the much larger man. However, although it seems to perhaps be saying something about the sexual act, Chris Cunningham himself is quoted as saying "It was...an experiment to me... It was intended to be completely abstract but it didn't quite work out that way and although it feels like its trying to say something, it isn't."
Whether or not it has a point, it is an intense and disturbing film that does what all great art should; it makes you think.