Redstethguy I don't think there is a simple answer to this question , some people like Brooklyn its all about the design and the different diaphragm or chest pieces :
Everything about their look is beautiful to me. The long tubing, the earpieces, and the best being the chest piece. I love that different stethoscope models have different looking chest pieces!
For others like Mashie its the person using the stethoscope whether they be male or female, doctor , nurse or partner
My answer is easy and simple, the person wearing it. I personally do not think of a scope as being sexy at all, but when it's hanging around Doc's neck, OMG, I mean seriously, OMG nothing makes me hotter quicker, nor my panties wetter. Just sayin.............MMMMMMMM!
And others like Brooklyn simple enjoy being observers or voyeurs and derive pleasure and a bit of a sexual thrill from it
For me, seeing a stethoscope in use on a guy is sexy.
For others its more the intimate aspects of being topless and having the cold diaphragm moved across the chest, in my experience most women get erect nipples from the excitement, anxiety , embarrassment or combination of all, a bit of sexual frisson so to speak.
Yet others like the closeness during the procedure if I'm auscultating a patient then I tend to look at where the bell or diaphragm is on the chest or back. Some patients don't like direct eye contact or you looking at their face directly. Others enjoy it, so depending on the response I may make eye or facial contact and kind of bonding experience. I have auscultated so many patients and so often each day that it really does not bother me if the try to make eye or facial contact or watch my every move.
So I really don't think their is any one factor which particularly makes a stethoscope sexy, I believe that its a combination that makes it sexy