Mayordomo para todo (1976)

Carlos, a young "playboy" who lives on the Costa del Sol, has a servant named German who has made him believe he has a degenerative disease by maintaining many sexual relationships, and that he will die if he continues doing so. But Carlos does not want to lose his playboy reputation, so German, his "faithful" butler, substitutes him in bed while Carlos convinces all his conquests that he prefers to make love with the lights off. But the plan is endangered when Carlos meets a girl and wants to marry her.