Warming up the ultrasound, Dr. Wolf took the head to his groin, resting it about his genitals as he stared into the monitor. Seeing the internal workings of the boy's abdomen gave the doctor a thrill. He'd been curious about the human body even before med school and residency. Now, he had a willing plaything with whom he could play doctor with! Pressing his cock up against Austin's hole, he watched intently as he gently slid himself inside. It was hard to see at first, but soon he was able to see his own shaft differentiated on the screen. The visual of his cock making its way into Austin's body only excited him more, making his already big cock throb at full force. He could see the distinct shape of his manhood with Austin's ass wrapped tightly around him. And with each thrust back and forth, he could see the boy's body yield to his presence. It was enough to drive Dr. Wolf to the edge of orgasm! But he took his time, watching himself on the screen as Austin's toes curled from the deep penetration...