My uncle Dale [may he RIP] used to live in south central Missouri and was a Veterinarian.
My brother and I used to get shipped off to his house every summer for about four years. [so my folks could have a break I'd guess.
We would work for Uncle Dale during the day and hang out on the weekends.
He had a party line and when he wanted to get a modicum of privacy he would announce to all listening on the line "ahem hello everyone Mr So-N-so and I are going to be talking Stud Horse for the next few minutes so if that sort of stuff bothers you it might be time to hang up."
He would then wait for a minute or so and continue with his conversation.
He said it usually worked like a charm and every so often he would hear the *Gasp* of one of the nosy's who was offended by the term "Stud Horse".
When the phone would ring we would count the rings. His ring was two long and two short.Man
... that's a long time ago.