This happened when I was 15.
My mom woke me up early in the morning to go to a regular doctors appointment. It was a routine checkup. I was nervous about going because I hadn't been in a long time and I already knew he would ask to see me naked. For some reason I had missed a few of the last doctor appointments and in the time between the last one and this one I had discovered masturbation and all the joys of sex. So in the car I was nervous but excited as well to be going. I could already feel myself becoming slightly turned on at the thought of a stranger seeing me nude. When the car finally pulled in the parking lot I couldn't wait to get inside, but I also wanted to turn around and leave.
When we walked in my mom talked to the receptionist and I took a seat. We only had to wait about 10 minutes but it felt much longer. At last they called my name and I followed a nurse back. She sat me down in a room and asked me a few questions like, if I have allergies, any special medication, that sort of thing. Before she left she asked me to strip to my underwear, and put a robe on. She also asked my mom to leave the room. My mom left and I was alone. I decided not to undress purely because I was incredibly nervous. I was starting to be more scared then excited.
I sat for a few minutes until my doc walked in. He was an older man, maybe in his 40's, but very nice. He tried to make me feel as comfortable as possible. He looked at my eyes, nose, ears, and listened to my heartbeat. He then told me I would have to undress into my underwear and I could put a robe on. I could feel my penis twitch as he said this.
I asked if he could turn around, and he did. I slowly pulled my shirt off, then dropped my pants and quickly threw the robe on. He started to listen to my heart again and other things. Finally he asked me to take the robe off and he had to inspect my penis.
I was so scared, but I decided to go with it. I timidly removed my robe and laid down on the table in my boxers. He came up beside me and laid his hands on my stomach. I felt tingles and shivers of excitement go through me as he started moving them lower. When he reached my waistband he asked me to lift up so he could pull my boxers down.
I closed my eyes and did so.
I was so excited knowing he was staring at my four-inch, uncircumcised, flaccid dick. He lifted my dick up and began to roll each testicle between his fingers. He asked my if I cleaned it regularly, to which I replied yes, but I couldn't fully pull my foreskin back yet.
He then took my dick in his hand. He said he had to pull the skin back as far as he could. I was so excited, and I was probably visibly shaking. As soon as he started pulling the skin back, I knew what was going to happen. I started getting hard. It happened so fast and there was nothing I could do to stop it. What he was doing felt sooo good.
Within probably 20 seconds my dick was at it's full hardness. He said, oh, it's ok, I can continue.
I probably turned bright red but I was loving it. I tried to apologize but just ended up muttering. He got the skin back to behind the head, then pushed it back. He began to repeat this, saying he had to loosen it up so it could be fully retractable.
The precum was dripping on me and he just said not to worry because it happens often. He kept moving his hand up an down on the foreskin, but it felt almost like he was masturbating me. It started to feel really good. And then, deep deep inside of me I started to feel an orgasm. I should have told him to stop but I didn't want him too.
He stopped doing the foreskin thing and began to just search all over it for bumps. As he was finishing he said, in the shower, pull the skin all the way back like this. As he said that he pulled the foreskin back like he was before and it happened. I shot cum all over myself. It got up to my neck probably. I felt my face become hot and started apologizing furiously. He said not to worry and just to clean up and he'd be back to finish with me. When he left, I felt bad and very embarrassed but I was still so horny.
As soon as he left I started stroking my dick furiously. I had to cum again. When I was almost done he walked back in and saw me, still covered in cum, jacking off, he was with the nurse. Then they both apologized and said they'd be back later. I came almost instantly again, and I don't think I could stop myself from moaning.
After all of this I finally wiped off and sat and waited. He was back in shortly and then I started to feel awkward. He said nothing of it though and told me I was healthy and could be on my way. On my way out, I wish I could say the nurse winked at me, but the look she gave me was almost evil.
I got back in the car and my mom took me home again. I ran to my room and once again jacked off thinking about what had happened. I still think about it and remember it vividly, as if it wasn't too long ago. I've been masturbating the whole time I've been remembering this. Hope you enjoyed!