Spreadlisa, I have a similar issue in the respect that I still haven't managed to commuincate the full scale of my desire to my partner. I tried once and got a fairly flippant/ambivalent reaction so I didn't push it.
However, a couple of days back as my partner was reaching the apex of an orgasm she grabbed my hand and said feel my 'heartbeat', which really took me back, and not wanting to miss the opportunity to exploit the situation asked if I could listen with my ear which was greeted with nothing short of glee. I now think from this tiny glimmer of interest I can slowly and patiently (no pun inteneded) build it into a medical secario: next time for instance i'll find a cock and bull story for introducing a stehoscope and see if it lights the touchpaper and take it from there.
So maybe try that with him. Start by getting him to feel your heartbeat in a similar way and build on it. Sorry if that sounds a little manipulative or insidious but people often freak to sudden change but can get used to almost any idea if introduced to it slowly – and it seems to be working for me.
Like yourself I am seriously worried about pressing the freak button but judging by the huge amount of people viewing the site – just a cursoury glance says there are 114 guests and 44 members online at this precise second – it suggests we're not quite as isoltaed and unusual as we think and probably won't get the awful reaction were are expecting.
Appologies for the lecture. Do drop me a line if you want to talk some more.