A Queens teacher was busted yesterday for fondling five girls in the back of his classroom while other kids did schoolwork, authorities said,

“Don’t tell anyone,” Simon Watts, 38, a third-grade teacher at PS 15 in Springfield Gardens, warned one of the girls he began sexually manhandling in September 2007, said DA Richard Brown.

Some of the girls — ages 8 to 10 — were abused over several years after Watts moved up to fourth-grade at the same time they did, authorities said.

His most recent alleged victim told her mother, who notified cops.