Duplicated (1980)

This film is basically a feature length collection of three early shorts directed by gay porn legend Toby Ross. The first segment is called 'Working Class Hero' and features two young blue collar studs getting it on, the second is titled 'Duplicated' and showcases two incestuous identical twins, first practicing karate and latter getting into some more intimate moves. The final segment is titled 'Freedom' and follows two young men as they watch a Led Zepplin concert film, which is being shown in an empty movie house, the two quickly get together and start their own private show.