Looking for a book by a British author. A man tells his story to somebody else. He was in a high position (judge?). Holiday at the seaside. While lying in the dunes, sunbathing, a group of adolescent girls approach him and watches (tease?) him. One of the girls visits him at his lodge, and a sexual relationship ensues. The parents of the girl find out about it, and he has to appear at court and gets sentenced; jail? At any rate he loses his position.