Eros Hotel (1979)

Three Italian couples and a single Italian girl, the title character, check in an Istanbul hotel. The hotel attendant is spying on the customers with a network of hidden cameras. The three female tourists are unsatisfied with the sex they get from their partners who are more into light kinks rather than straightforward love-making. The hotel attendant sells them an aphrodisiac he has manufactured. But will he himself be able to get Daniela?