Damage (1992)

Jeremy Irons, David Thewlis, Peter Stormare, Juliette Binoche

A member of Parliament (Irons) falls passionately in love with his son's fiancée. They pursue their affair with obsessive abandon despite the dangers of discovery and what it would do to his complacent life and his son. Completely obsessed, he wants to give up his current lifestyle to be with her.