A TEACHER pleasured himself in front of pupils during exams, a court heard yesterday. Shay Kernaghan, 27, put chairs either side of his desk to hide what he was doing, but one sixth-former said: “It was obvious. He went pink and started shaking his hand.” Business studies teacher Kernaghan, who has since left the London school for Muslims, denies eight charges. Case continues at Southwark Crown Court.