This thread reminds me of my first girlfriend just half a century ago.
I was a very shy teen-ager with a strong rectal temperature fetish and I spent my youth masturbating, often with a thermometer up my ass, daydreaming about all the girls I did not even dare to speak to.
Eventually, at 21, I found a girlfriend, Chrisrine, or she found me, and we started a wonderfull romance and I can say I learned a lot about sex from her , except for one detail, her attitude to rectal temperature. A few days after she had taken my virginhood, I came to our rendez-vous with a rectal thermometer. .She was very shocked and we allmost broke up that day. She thought rectal temperature was something disgusting and may be a sign that I was in fact gay. During our four years relation, she allways refused to let me take her temperature or to take mine. I remember one day I was sick and beg her to take my temperature, she answered: ''I am not your mom''.
Our relation was anyhow a bit strange as she was studying aboard and we were separated most of the time. When I confessed to her that I masturbated with a thermometer up my ass, thinking about her, she made me promiss to stop, not masturbating, but doing it with a thermometer.
We eventually slowly separated and Maria, my second girlfriend, was quite the opposite to Christine. Maria was very much into medfet and she had set the rule that every time we were to have sex, she would give me a physical, ending with her taking my rectal temperature on her lap. I was in Heaven.