We Need a Larger Sample

"I'm sorry, Rob. I should have let you finish your second ejaculation." Dr. Mitchell reached into his bin of exam gloves and pulled one on his right hand. He walked to Rob's midsection, exposed on the exam table. "Close your eyes and relax, Rob."

Dr. Mitchell reached between Rob's thighs and wrapped his gloved hand around his penis. Using a firm grip around the shaft and a gentle thumb on the glans, he stroked Rob's penis.

"Doc, I'm not sure... "Rob's protest faded into a gentle moan. He watched as the head of his penis kept disappearing behind Dr. Mitchell's thumb and then burst through his fist again. With each thrust he saw, he felt an accompanying wave of pleasure emanating from his groin. It wasn't long before he was losing control. "Fuck. Dr. Mitchell. I'm gonna cuuuuuuuuuuum!" Rob's hips bucked as he thrust his penis deep into his doctor's fist. His penis ejaculated rope after rope of semen, with each thrust. One hitting Dr. Mitchell on the side of his lip.

Rob felt his body go limp as he laid with his eyes closed, trying to recover his breath.

Dr. Mitchell gave Rob's penis one final firm stroke to release any additional semen that had not been ejaculated. He turned away from Rob, licking his lip to tase Rob's semen. "I'll help you clean up." he said as he pulled another warm towel form the bin.

"Thank you, doctor." Rob took the towel from Dr. Mitchell. "Can I get dressed, now?" Rob wiped his semen from his stomach and chest, then stroked his penis with the cloth, cleaning any remaining fluids.

"Of course. While you get dressed, I'll prepare a few slides of yours and your dad's semen. We can take a look together."

Dr. Mitchell removed his exam glove and tossed it on his desk. He retrieved the semen collection containers from the machines and checked the labels. He prepared a sample of each container and placed them under the microscope. He switched on a monitor as Rob walked up pulling his shirt on.

"This won't show us anything new, but I though you would like to see your semen compared to your father's. Yours is here, on the left. Your dad's on the right. You can see both samples have a good count, and the motility is very strong."

They both looked at Rob and Tom's sperm swimming around on the screen. Rob had that strange feeling again that there was something enjoyable about seeing his sperm swim next to his father's.

"I'll do more tests in the lab on the semen itself and monitor these two samples over time to see if your sperm last as long as your dad's." Dr. Mitchell switched off the screen and stowed the sample containers. You and your dad did a great job today. We'll figure this out."

Dr. Mitchell showed Rob out the door. "Checkout at the front and schedule your follow up for a week from now."

"Thanks, Doc" Rob left the exam room.

Dr. Mitchell slumped back in his desk chair and let out a big sigh. It can be so hard for him to maintain professionalism when he has to administer tests like that. If his patients only knew how turned on he gets watching them have their semen extracted and collected...

He wiped his brow and let his hand slide down his chest to his belt. Unbuckling his belt, Dr. Mitchell felt his cock jump in his pants. He unzipped them and tugged them down to his hips. His coat spread open, he pulled his penis out of his underwear, letting it free after an hour of confinement. He picked up and unfolded his exam glove. It was still wet with Rob's cum. Dr. Mitchell put it back on his hand and wrapped it around his cock. He shuddered as he felt the wetness on his shaft. Rob's semen squished through the glove and collected on Dr. Mitchell's penis head. He wiped it away with his thumb and masturbated his erect penis, letting Rob's semen lubricate his strokes.

Dr. Mitchell groaned. "Rob. Fuck. Your semen is on my penis." His hips started shaking. His butt clenched, he thrust his pelvis into the air as he ejaculated onto the wall above his desk. "UUUUGH" he groaned as he shook with each post-orgasm spasm.

The doctor took off his exam glove and tossed it into the trash. He looked at his handy work on the wall as he put his soft penis back into his underwear and zipped up his pants. "It's nice to add another one to the collection."