Cruel Intentions (1999)

Sebastian and Kathryn are two half-brothers who go to the same elite school in New York and challenge each other to a perverse bet around Annette Hargrove, a student who plans to remain a virgin until she marries, whom Sebastian will try to seduce. A nineties transposition of the novel Dangerous Liaisons, which thanks to a quartet of very good performances (Sarah Michelle Gellar, Reese Witherspoon, Selma Blair and Ryan Phillippe) creates an atmosphere with a tone that feels very real.