Elio Perlman is spending the summer with his family at their vacation home in Lombardy, Italy. When his father hires a handsome doctoral student, the curious 17-year-old finds himself developing a growing attraction to the young man.

An American couple, Paul and Marianne, spend their vacation in Italy and experiences trouble when the wife invites a former lover and his teenage daughter to visit, which leads to jealousy and dangerous sexual scenarios.