We use the word "pet" exactly the way denuseri says. A term of endearment. When Lady K calls me "pet" I know all is well. If I hear Her say "come here pet" it normally means I am in for some kind of reward. If I hear Her say "get here slave" I know things aren't so good! I think it's sort of like if you call your partner "dear" or "honey" or whatever all is good. If you use the first name it might get their attention a bit quicker and set of an alarm that somethings up. Anyway, that's how we use the term "pet"