During Francoism, the Spanish musical cinema was a highly popular and lucra­tive genre, since it allowed movie directors to avoid politically sensitive topics by turning their productions into vehicles for catchy songs. This paper analyzes Más bonita que ninguna (1965) by Luis César Amadori through the lens of Mi­guel de Cervantes’s Las dos doncellas (1613), in which the (former) child prodigy Rocío Dúrcal embraces the double role of Luisa/Luisito after being tricked by her boyfriend. By exploring cross-dressing both as a trap and an expression of gender identity, it further examines the role of marriage. Keywords: marriage, cross-dressing, gender identity, trickery, Cervantes, Rocío Dúrcal