tutor colin turnbull , 69 , was found in a ` compromised position ' with rozina khanim by a governor at the £ 13,000-a-year independent priory school in edgbaston , birmingham .
the fee-paying school 's facilities manager kevin bird walked in on the pair while they were engaged in a sex act during an entrance exam day .
the school was said to be packed with pupils and parents when mr turnbull and ms khanim - who describes herself as a model - were walked in on .