Simple. I have Daddy issues. When I call a fuck boy "Daddy," I'm not thinking about MY father. I think of the role a "daddy" provides. Or rather, should provide.
A good daddy is kind, attentive, warm, and treats you with gentle grace and love.
I want that, but in a lover. I want someone to treat me like a precious, sweet little thing. I never had that from my actual Dad, so I don't think of my father as "Daddy."
My Daddy is the guy who takes care of me, adores me, and knows I adore him right back. He's the one that gets to see the best and worst in me, because he chose me. Flaws and all, a Daddy is love.
My father was the guy who used to kick the shit out of me for having black friends and literally spat tobacco juice in my eyes if I crossed him. They aren't the same thing.
...I just depressed myself.