OK heres a serious answer and NO pun or stupid things intended.
I was raised on rectal temps as being the most accurate way to check a temperature since birth to now. Of course whether used to the age someone should or shouldn't have it until , somewhere along the lines of puberty or lil before it the child either develops a love or the hate for it .
In the result of a hate being for it , it either was because the parent was too swift with the rectal temp, the child just hates things in his/her rectum or they had some kind of abuse that led to them hating it .
In the love for it the child either didnt mind it being done as being told it was the most accurate they learned to accept it and without hating it. or they just like the feeling of things secretly not telling parents of the things in thier rectum which is thier preferance .
Now given the facts fetishes from love hate can result .
I on the hand yes may have a Fetish with it, but however even before that came about , I still believe and feel that without arguement that the rectal temp is by far the most accurate and whenever i am not feeling well , i use the rectal temp.
Using the rectal temp is not a perverted thing but how you sway the rectal temp is a different story. If its in play fun is fun . But if evryday you find yourself inserting the thermometer in your bottom for just any reason on a consistent basis , yes i would question , what in the hell is the intention of that? examine why you are doing that .
Each person is the only judge of themselves , so internal jury's of each soul , let the judging begin , to each of thier own….