Based on a true story
My sister and I had always had a great relationship. I was the younger "protective" brother and she was the older "troubled" child that always had me on my toes. You see my sister and I were the only ones we could count on after my dad died in a plane accident. My mother was a local gynecologist, and always busy with patients and rarely at home. So that left my sister and I with a lot of time together to talk and lounge around until mom's arrival.
One afternoon, Amy confided to me that she thought about sex all the time. Anything sexual was never too taboo for her to discuss with me, after all I was the one who often kept her out of trouble. Amy at the age of 22 attended a local community college, and I was 18 and in my senior year of high school. My sister was a tease and sometimes wore clothing in the house that would get my attention. One Friday after school, I was coming up the stairs when Amy appeared out of the master bedroom wearing moms favorite white teddy. I tried to look away but couldn't when I noticed the teddy had what I called "see through fabric". I could clearly see the outline of Amy's bush with her D cup breast matching her thin waistline and wide hips like a goddess. Her nipples pushed into the fabric catching my stare and her aureoles were the size of a tennis ball. I asked her what she was doing and she simply said "nothing, just wondering what it would look like".
On days when mom wasn't around we would often play games to pass the time. Monopoly, chess, and cards were some popular ones, but playing doctor was our all time favorite. In the house mom had a spare bedroom made into a examination room for the interns she taught. Having real equipment to play with made it exciting as I played Doctor Ryan wearing my white jacket, and Amy wearing shorts and a tank top played the patient. I would get Amy's height measurements at 5'5" and then look at her throat and ears on the examination table. With a full report making sure she was in top running order, I tried to keep things at an innocent level.
One day I had Amy on the table fully clothed when I was checking her heart rate. The stethoscope was getting stuck on her low cut blouse and her huge tits weren't helping. As we were just playing, I was almost ready to skip to the next part of the examination when Amy said "doctor shouldn't you just have me take off my blouse?". I looked at her in disbelief, knowing that mom could be home at any time.
I said to her "what if mom would catch us?"
She replied "I'll just run to my room if she comes home its right down the hall."
With a reluctant "OK" I helped Amy off with the blouse and put it on a chair next to me.
It was the first time I had ever seen Amy's bra covered tits other than in the white teddy and it was always a jaw dropping experience.
After hearing her quickening heart rate and getting more nervous about being caught, Amy said to me "doctor isn't it time you checked my breast for lumps? After all I don't think we did that on my last visit."
Looking nervous I reached for my clipboard to act like I was actually reading the last time I did a breast exam to clear my head and decide if I wanted this to go on.
Amy again spoke up after clearing her voice " doctor without my bra on."
I timidly agreed and reached around her back to unclasp the huge boulder holder while holding onto my thoughts of what would happen if mom saw the two of us like this. There were 7 clasps undone and the bra still didn't unfasten. I had some girlfriends who had maybe 4 clasps but never this many. Fearing I had lost my touch, I looked up at my sister waiting patiently for help. Amy just smiled and said, "silly you almost had it" and she removed yet another garment after undoing the final clasp.
I was taken back as my sisters breast were freed from their confines and brought to my unabated gaze for the first time. Her nipples were perfect her globes of flesh were so firm you could knock golf balls off the top of them. I looked them over for a long period of time when Amy interrupted and said, "are you going to feel for lumps or what doctor?"
"Of course" I said, "what kind of doctor would I be if I didn't?" My hands roamed around feeling her huge milk makers and paying special attention to her pencil eraser shaped nipples. I don't know what came over me at that moment, but I bent down and sucked on both nipples, fully expecting Amy to end our play time together. I looked up and was really fearing the time as moms arrival was sure to come when Amy spoke yet again with another medical question, "do I feel warm to you doctor?"
I replied "I'm not sure, I think to be careful we should take your temperature" I looked around the room and sure enough there was moms glass flask full of mercury thermometers and soaking in alcohol. Funny I thought, I always use the digital one and can't seem to find it. Amy must have moved it earlier. I approached Amy and presented her with a thermometer and tried to insert it in her mouth.
"Yuk! That's not the way doctors do it" she shouted topless and naked from the waist up.
"Excuse me, but I'm the doctor and I think I would know how to take a patients temperature."
She looked at me with that naughty smile and said, "that's not what I mean, you see there are two colors of thermometers in the flask red and blue. The blue ones are oral and the red ones are anal. Your holding a red one and you know where that goes right doc?"
I grinned, "well maybe you should decide where your temp is to be taken, close your eyes and choose a thermometer from the flask Ms Ryan" I stated as professionally as I could.
Amy closed her eyes and although I saw her peek, picked out none other than a red thermometer.
"Sorry" I said. "I'm afraid I'm going to need you to assume the position on your hands and knees with bottoms up. Looks like it's your unlucky day."
My sister looking brave said "I guess that depends on how you define unlucky."
Amy laid back on the examination table and watching her tits flop to the sides of her chest, I began undoing her belt on her khaki shorts while looking down at my own rocket cock trying to launch its way out of the silo. Amy assisted by lifting her bottom to help me slide her shorts off along with her shoes and socks.
Gazing at my sister on the paper covered table that made a distinctive crinkling noise, I made my way over to the cabinet where latex gloves and KY Jelly were stored. After being satisfied that there was enough KY on the thermometer, I came back to my panty covered sister who had turned over and assumed the position with her ass to my full view. Anticipating my first look at her naked bottom, I grabbed the elastic of her pink cotton panties and began nudging them down. Amy resuming her role as patient stopped me and loudly stated, "I know this isn't a good time doctor, but I've heard you are writing a book about the female anatomy and looking for research am I right?"
"Yes.....yes I am Ms Ryan", I said dying from expectation.
Amy looking over her shoulder with a look of someone about to have her temperature taken up her ass replied, "well it's OK with me if you use your camera and camcorder over there to record my examination for your medical research to complete your book if you want to."
Thinking of the possibilities of sending my friends e-mail attachments with pictures of my sisters naked pussy, I realized I should hurry up and take the porn pictures before she changed her mind. "Great idea Ms Ryan, but I should make you aware first that a lot of people are going to see these pictures in my new book, people you may or may not know."
My sister now rubbing her panties into the lips of her sex looked back again and replied "may I know some examples of whom may see these pictorials doctor?"
