Well, I do have a friend whom I call daddy and I've been calling him that for probably about 5-6 years. It started, at least I think it started, as a harmless nickname and his girlfriend on the message board was mommy. Being all cutesy and annoying to the biggest, baddest internet bully in the vicinity and getting away with it was, and is, appealing to me.
I can't say I trust him all that much, though. Not in such a way that I could ever see myself in an full relationship with him. Know him a bit too well for that if you know what I mean.
But I do get positive reinforcement for irritating others. ^^
Actually, now that I think about it, I've also attached "mommy and daddy" to the friends I was a third wheel to. I think that was more of a "Hellooooo? I don't wanna watch you suck face all night." type thing though.
In college, my roommate was "mommy" (since we decided she was being motherly and protective), our suitemate was "(the) baby," and I was "puppy." (Unfortunately, one of our friends found out that I do, in fact, bite.)
And most recently, you know that joke response: "Call me." "What do you want me to call you? XP"? Last April, I pulled that on one of my closest friends (though about 3 hrs away by plane), and after clarifying that I was not asking "when," but "what" to call her, she replied with, "I don't know. 'Master'?" A beat passes. I respond, "Okay, Master!"
I called her that for quite a while, and if I objected to something, she would pull it out and I would obey. I'm not quite sure how long that lasted exactly. It's kind of subsided and "mastur" has worked its way into a standard rotation of nicknames.
So, have I babbled on too much yet?