Mark had just got off with Dr. Phingerphuk using a device to jerk him off, and then the doc asked to do a little experiment with me. He said that he would make it worth wild for me, and would first get the nurse to come in to prepare the room. We moved Mark off the table and into the chair that I had been sitting in. Then, once the nurse was finished, Dr. Phingerphuk returned closing the door behind him. I took off my shirt, and my shorts and briefs as well. The doc started to examine my cock right away, and noticed that I had a sunburn on my dick. He turned to the side to grab something and he asked me at the same time if I had ever had anything in my butt before. I thought that maybe he was asking me a trick question, but he wasn't. I had responded with a yes, and he got very excited. To get started he had me get on the table doggie style, and applied some lube to my asshole. Starting with a butt-plug he said that he wanted to get my ass use to having something in it. He smothered the plug in lube and then pressed it against my hole. As it started to work its way into my ass, he pushed it in a little, then pulled it back out some. The doc had me ride the plug to get more comfortable with it. Once the plug was all the way in, he gave me some anesthesia to ease the pain. Slapping the end of the plug he got me to relax and told me not push it out. Taking the plug out, he had me turn over and repositioned the table to a better position. The doc prepared a thick, large, dildo hooked up to a machine that would vibrate. As he started to put it in, I know that my body was going to go in some shock. I reached for the toy, and took over inserting it into my ass. I did it at my own speed, and was able to get it all the way in rather fast. I held my legs up for a minute because it felt more comfortable at first. The doc pointed out to put my legs down, and I just tried to relax a bit. Turning the machine on, Dr. Phingerphuk started to make the toy vibrate. He started with a very low setting at first to make me feel comfortable, and waited for a minute. After which he wanted to speed things along. He cranked the machine and started to play with my dick. He pointed out for Mark to help me out, since I sucked his dick before. Mark hopped up and started to take my dick in his mouth. He gives good blow jobs, but for some reason I couldn't get fully hard. I felt a little strange with everything that my body was feeling. The doc grabbed a handful of lube and started to stroke my dick. He tried to jerk me off for a while and then he had me take over. I stroked my cock just like I do at home, and was able to get close to cumming. I came a huge load, and my hand and dick was covered in cum. The doc asked me how it felt, and I told him that it felt great. The whole time I just wanted to cum with that machine pulsing in my ass. Next we had to start the process of pulling the toy out of my ass. Dr. Phingerphuk took it out very slow, and once it was out he told us that he would like us to come back. He said that he had more for us to do if we wanted to come back after hours one night when the clinic was closed. We will have to wait and see if the doc calls us to come in.