At 71, I have been having a strong rectal temperature fetish thoughout my whole life.
My last girlfriend dumped me two years ago and I am alone to take the care of my temperature..
As I did with my partners, when I take my temperature, I like to twirl the thermometer, but I must say my favorite thermometer movement is to let it go very slowly back and forth into my rectum as it registrers, as if it were making love to my ass. Of course, I like to keep the thermometer into my rectum much longer than the requested time and I use good old glass mercury thermometers.
As a matter of facts, I have come to consider rectal temperature taking as a way of making love, just like anal or oral sex, .and a very intimate one. Imo, it must also be reciproprocal, I take yours, you take mine.
A few years ago, I had a several months very intimate relation with a very classy lady who was very much into rectal temperature. We spent nights playing kinky games with thermometers, both stark naked, but she never alliowed my penis to penetrate her. I would not go that far and l confess I have had a lot of happy ''normal'' sex with my rectal temperature partners.