I was waiting for the doctor to come in after Nurse AJ finished his part of the exam with me. Sitting there naked on the exam table, Dr. Phingerphuck came in and introduced himself. He said that I was randomly selected to participate in a prostate study. The Doc pointed out several different instruments on the table that he would use at the same time my penis would be massaged. Afterward he would collect a sample for the lab, and I would be okay to leave. The first thing Phingerphuck wanted to do was listen to my heart and lungs, and he could tell that I smoked. Putting on his gloves he got ready to start the exam, and I just watched everything that he did. Picking up the smallest tool, he said that we would start out slow. Adjusting my body on the table, I finally got in a comfortable position with my feet in these stirrups. Reminding me to breathe, the doc placed the tool against my hole and started to press in. Pushing in at a steady pace, it seemed like the Doc was able to get it all the way in my ass and it didn't feel that bad. Dr. Phingerphuck started to play with my dick, stroking me with his gloves on and his hands covered in lube. While he would do that, he would check on the instrument by tapping on the end of it. After a while he decided that he was going to take it out to try something else out. He said not to push as he was taking it out, to just allow my body to naturally push it out. Putting it to the side he reached behind the exam table and brought out the next instrument. Rubbing it with his hands he was applying lube over the whole thing. Then he placed it at the entrance of my asshole, and lightly pushed the toy inside me. When it was about half way in he started to move it a little around in a circle, pulling in and out, and my hole allowed more of it to go in. My cock was getting rock hard as I played with it, and the Doc asked me how it felt. I told him that it was a good feeling. Once in a while a moan would slip out, and with all the sensations that I was feeling I lost concentration on everything the doctor was doing. The last thing that the Doc wanted to use was an instrument that was designed to go specifically in the ass. He showed it to me, and it was a really weird shape. Dr. Phingerphuck took the time and care putting it in my ass just like he did with the others. A technique that he told me to try was to clinch the toy using all the ass muscles I had, and then releasing immediately. It sent this rush feeling throughout my body, ultimately getting my dick rock hard. At one point, I even did a couple of reputations of clinch and release, and the Doc could tell a difference in my dick getting harder. Phingerphuck was pumping my dick pretty fast, and I knew that I was moments away from shooting a load. I held back as long as I could, in the hopes that I wasn't an early shooter for the Doc. I let out that I was going to cum and he told me it was okay. When I came the load went directly on my stomach pooling about halfway between my belly button and my cock. The Doc kept stroking until I was finished having my orgasm and squirting out cum. Then, he proceeded to show me what part of my cum came from my prostate in results to him using that last toy on my. I asked him where I could get one, and he gave me a website. He told me on my way out if I wanted to see him again that I could make an appointment with the Nurse. I figured that I would get cleaned up and think about it.