Rent Come Play with Me (1977)

Sue (Mary Millington), as the leader of a horde of horny girls who take over the running of a remote health farm.Their naughty fitness treatments certainly give new meaning to being in 'rude' health and, when a pair of bungling forgers hide out at their country house of ill-repute to escape the police and rival heavies, the movie climaxes (oof!) with a no-holds-barred orgy that would make a docker blush.