What's a "daddy" in gay lingo?

My gay friend calls me daddy at times and some of my other friends say that's not cool. One of my female friends says that my gay friend gets jealous if she calls me daddy and almost flips out if she gets to do something that he doesn't get to do? Your thoughts on what this means? Oh, and I'm bi-curious, not gay although my gay friends say that the "gaydar" is undecided on me lol. Thanks for the help!