Tonight on my drive home I saw a cat in my neighborhood.
That got me thinking about the cat we used to have.
We called her "Kitty" (original name, I know, but there's a story behind it), and she also had a variety of nicknames, one of which was "Kissy". Although it is obviously related to the generic nickname "kitty", I have noticed that it doesn't feel right to use "Kissy" with other cats; that name belongs more to her.
Then I started thinking about the phonological derivation of "Kissy" from "Kitty".
By the time I got home, I had realized that it was a simple change of manner of articulation, changing the alveolar flap in "Kitty" to an alveolar fricative.
You know you're a linguist when you discover the phonological rule by which you made your cat's nickname.
By the way, we also used to call the cat "Kiss", which is obviously just a deleted version of "Kissy"...