It was only one time that my sister got to see me get examined. My sister is 3 years younger than me. My sister had allergies and the pediatrician my mother took her to was my doctor as well.
I remember that my mother had scheduled both my sister and me to see the doctor. She went first and the doctor didn't really examine her the same as he did with me. Not sure, private exams what he did with her because we normally did different times and separate appointments.
Because of the toxic home life I was living in, my sister would see me in my undies most of the time and she would see that I would get an erection many times showing in my undies (but that is another story, check out my profile and other stories regarding my home life).
I was 15 at the time and my sister 12. I knew and I was very nervous because my exams always included a genital exam as my mother would watch and since the exam rooms were small, you were able to see everything. I was told to get undressed by the nurse, as she weighed me and took my height. The nurse took my temperature using the anal thermometer (they took temperature like that back then). Then she instructed me to get onto the exam table as she took my blood pressure. Then told me to wait for the doctor to return.
Once he came into the exam room, he would check my eyes, nose, and throat and listen to my heart. Have me lay down palpate my stomach and work his hands down my underwear. He would instruct me to lift my butt, and he would remove my undies. I would just lay there, nude with a semi-erection. He would comment to my mother, that my pubic hair is growing in and that he examined my pubic area and felt my testicles and he would tell my mother that my testicles were normal. He would go to the draw and take out the tanner balls and measure each testicle and compare the size I was at for my age which was normal. I would already have an erection.
My mind would be racing and my penis was throbbing along with my heartbeat. I just looked up at the ceiling tile when the doctor would place his hand at the base of my erect penis and with his other hand palpate the shaft of my penis. He would then slowly feel my frenulum and rub it and I can feel the build-up of cum starting to have my orgasm. With a few more rubs of the frenulum, I would ejaculate.
In full view of my mother and sister, they all acted along with the doctor as this was a normal day at the office. As I was coming down from my orgasm, the doctor went to the sink, removed his latex gloves, and cleaned me up with tissues. I was to get dressed and he spoke to my mother in private as he normally did. I was waiting in the waiting room, along with my sister, and said nothing.