I have a strong fetish for rectal temperature and this has influenced the way I masturbate.
When I masturbate, I often insert a rectal thermometer in my rectum and I am sure this increases my feeling as I play with my penis.
So, my fantasies tend to concentrate on my rememberance of good température taking sessions with my successive girlfriends.
But, I must say that, as I get older, my fantasies often go back to a special circonstance, my last high school medical annual exam when the school doctor took my rectal temperature standing up, first time ever during my school years
And, as time goes, I have developped this story, making it more and more exciting, if not pervert, and more and more unrealistic.
So as one hand holds the thermometer and plays with it and the other takes care of my penis , I have imagined that the doctor, after taking my temperature, wants to have a second reading, in a différent position, on all four on the exam bed for instance. In a further fantasy, she asks me to masturbate in front of her, still with the thermometer inserted.
I have also imagined that the young doctor makes a handjob or a blowjob on me, the thermometer still registering in my ass.
Recently, I came out with a further development.The doctor informs me that a girl of my class, whom I have a secret crush on, and I have been selected on a special program. So I end up fucking my class mate on the exam bed,, she enjoys it and I do, as the doctor is still holding the thermometer in my ass, having it go back and forth in my rectum, in rythm with my love making movement.