Roberto (Luigi Giuliani) and Luisa (Rocío Durcal) are a couple but are not as sincere as they should be. She tells him she works at Telefónica when really she sells cigarettes at "The Green Windmill" cabaret. She's surprised when she discovers plans for a bachelor party there, organized for Roberto, who is going to marry a wealthy heiress. To prepare her revenge, Luisa adopts the role of Luisito and faces Roberto in disguise.