Thirty-year-old Richard Hovan, a former math teacher at $40,000-per-year-tuition Riverdale Country School in the Bronx, was charged on Monday with two counts of third-degree criminal sex act and endangering the welfare of a child for having a sexual relationship with a 16-year-old student. The New York Post reports that much of the misconduct took place at a Chelsea co-op Hovan had been sharing with his then-fiancée, who nearly discovered the girl in the place. A source at Hovan’s 101 West 23rd Street building said Hovan brought a “very young-looking” girl home several times when his fiancée was away said that one time: “I saw the girl climb out of the fire escape from his apartment and hide there. She waited until [the fiancée] was gone and then she came back in.” Hovan pleaded not guilty.