Hi Jacara,
no, neither my sister, nore me, studied medecin together, unfortunately :-(
But this a a topic, which enormously accelerates my fantasy! When I was young, I had a class mate who had an older sister, who studied medecine, and I always imagined her in her white doctor's coat with her red stethoscope around her neck. I didn't dare to tell her, that I'd love to see her so...
I'd also very much liked to ask her brother, if she practized on him - auscultation, of course! You know, I'm mad of the small sound which comes, when you lift off the diaphram of the Stethoscope the moist skin of the exited body of a girl with pounding heart :-) This makes me cum almost instantly!!!
I' so much loved to ask him if he has ever experienced that - but I didn't dare. I feared that he calls me a pervert, and he tells his sister. And we would lose our friendship. So, I didn't say anything, but masturbated regularly, when I came back home from their place, after having seen them and imagining her being the doctor and having stethed her brother and me together... ;-)