The Exchange Student (1967)

Charles Bosquier, a role apparently written for French comedy superstar Louis de Funès, is the dictatorial headmaster of a French strict boarding school. No father could be deeper shocked to find one of his own sons miserably failed his exams, and too embarrassed to enroll him for his own summer-school, so he sends Philippe to England as exchange student. Philippe planned to save his sailing plans with friends by sending fat nerd Stephane Michonnet to England using his name, which comes out when Michonnet gets indigestion. Meanwhile Charles expects his spoiled favorite son, Gérard, who tells daddy about all the other schoolboys for money, to chaperon Shirley, the daughter of his English counterpart MacFarrell, but the girl gets all French boys horny, so even his perfect record is soon gravely soiled as dad spies on them, and he and Shirley join Philippe and his friends. Now the headmaster chases the kids' yacht -incognito, to avoid a scandal- all the way to England, where his colleague soon joins him, and further...—KGF Vissers