El diablo en vacaciones (1963)

A mature man habitually pursues young girls, for which he is abandoned by his wife. The devil intervenes, offering both spouses, separately, to regain their youth. The two agree to make up for the lost years, but the devil makes them both join the same gang for a summer. The husband, who now feels comfortable, falls in love with his wife again without recognizing her, just as she will not recognize her ex.