Dr. Wolf introduces Dolf to the boy in a private room at his office, having told the nurse all about his outrageous experiments with ultrasound. Dr. Wolf has developed a unique technique which enables a hard dick - mid-fuck - to be watched on the screen thrusting deep inside a boy’s body. The moment Dolf heard about it, he was hooked on the idea and desperate to see it in action.

The doctor immediately orders Austin to take off his clothes. The boy obediently does as instructed, knowing that his familiar buddy Dolf is going to end up inside him before any of them leave the room. Dolf has had a lot of fun with Austin before, but he’s never had the chance to see his hard cock in him like this!

The doctor scoops him into his arms and kisses him passionately, fondling the boy’s dick and groping his ass simultaneously. By the time Austin’s underpants are pulled down, the boy is good and hard and ready for anything.

Austin is soon groaning and moaning in a state of deep arousal. Dolf sits and watches the floor show, running his fingers slowly over the giant bulge in his loosely-fitted pants. The boy barely comes up to the doctor’s shoulders and Dolf finds the huge contrast highly exciting, knowing his enormous, throbbing member is likely to stretch Austin’s tiny little hole in an almost obscene manner!

Austin sits down on a hospital bed and the doctor places his feet in stirrups which force his legs sluttishly wide apart. Dolf is then invited to stand up and drop his scrubs. The boy watches Dolf as he moves over to the tables, hugely turned on by the wanton look in the older man’s eyes.

Dr. Wolf guides the boy’s trembling hand to the rock hard bulge in Dolf’s underpants and encourages him to squeeze and play with it to get a clearer sense of what’s coming his way.

Austin is plainly excited by the thought of having Dolf's massive member inside him. The older man purrs appreciatively and runs his enormous, tanned hands over the boy’s smooth, porcelain-white belly. Austin soon finds himself gagging for Dolf’s dick. He can’t wait to feel it… and more importantly see it… on the inside!

Dolf drops his underpants and his cock bounces out excitedly. This is a medical experiment and time is ticking, so there is no time for foreplay. Dolf casually lines his dick up with Austin’s hole and starts to push himself inside. His dick is particularly thick. Austin closes his eyes and shivers as his ass muscles are inexorably forced apart. He whimpers helplessly as Dolf pushes himself deeper and deeper inside.

Dr. Wolf issues calm instructions at all times to make certain that his two subjects are hitting the right physical angles for the experiment to be at its most effective. Once satisfied that everything is in order, the doctor switches his ultrasound equipment on. A small screen by the exam table instantly lights up and a grainy image appears showing Austin’s bladder.

Dolf pulls out before pushing his plus-sized dick back into Austin’s tight hole again. The outline of his thick member suddenly appears on the screen, moving gently along the side of the boy’s bladder. It’s a fascinating sight, one which makes Dolf super horny. The nurse slides his dick in and out of the boy, varying the pace and intensity of his strokes to see how the visuals change in response.

Dr. Wolf continues to give orders. He’s on a quest to record the clearest and most arresting internal footage yet. Watching the images link Austin and Dolf in a most profound way which they both feel with great intensity.

Dolf quickens the pace as the waves of lustful excitement start to engulf him. Austin’s body is now humming with sexual excitement.

Dr. Wolf asks Dolf if he’s up for shooting his load inside the boy to find out if the ejaculate can be seen on the screen. It’s the ultimate goal in this particular experiment and the doctor has not yet caught this most intimate of moments on camera.

Dolf is excited by the thought and willing to try so, continuing to thrust with increasing force. The table starts to shake. Austin grunts and wails as precum drips from his dick.

Dolf suddenly feels the semen rising. He stops dead and allows the cum to explode out of him. Grainy white clouds instantly form around the tip of his dick on the screen. It is beautiful and highly valuable footage which Dr. Wolf is excited to publish when the right time comes. In the meantime, there is plenty more experimentation to be done…