The doctor, a master of the backdoor, begins his anal exploration, spreading the patient's ass cheeks wide. He runs his finger around the puckered hole, feeling the anticipation. With a quick lube, he slips his index finger in, twisting and turning, feeling the patient's ass gripping him. The patient's moans fill the room as the doctor adds another finger, stretching the asshole wide. The doctor, now throbbing with desire, replaces his fingers with his thick cock, pushing past the tight ring, and begins to fuck the patient senseless, their asshole gaping and clenching with each thrust.