I honestly don't see the big deal in it. I have in the past with a few men I've been with. Online and in person relationships. It doesn't happen in every relationship I'm in either. It all depends on how he makes me feel. I have a submissive side in me, but it doesn't come out to play for everyone I date. It just lingers there until she wants to come out. She's rather shy. It has nothing to do with biological daddy issues. I do not think of my father in any sense when I'm being sexual with a man I care and trust. That is just gross. I call him daddy because he protects me, he takes care of me and he loves me.
I certainly wouldn't suggest moaning it out the first time you have sex with a guy. You might want to talk to him about it. Some men might not be down for it at all. From what I've seen, most don't care. Though some do lie about it and say it's okay, only to find out later they didn't like it. It's their dumb-ass fault for lying.
So yeah, just learn how to communicate with your lover. If you can fuck em', you can talk to em'. Simple as that.
Story time with Felix, gather around kids.
About a year ago I started dating this girl I met on a hookup site and it got sexy pretty quickly. Blew me in my truck on the second date so she was pretty wild. So a few days later I was playing with her pussy, making out, you know.. and I started rubbing her clit just right and she starts moaning and saying "Oh daddyy... Oh daddy... Oh daddyyyyy" over and over again. To be honest it threw me off a bit. Being called daddy always throws me off a bit the first time a girl does it, then it doesn't. But the way she was doing was turning me off so I slowly moved my hand up to her mouth and covered it... She tried to say daddy again and I firmly covered it so she couldn't talk. She then wiggles her mouth free slightly and bites the fuck out of my hand. Like, hard. And I look at her like "bitch, you trying to get slapped?" And she looks at me straight in the eye and with a totally serious look on her face and says, "What's the matter daddy, you afraid mommy is gonna hear?" Then she bit her lip like she was being all cute with her shit. Boner gone. (for a little bit)
This is not something I would be comfortable with. He might be into it... but I'm not.
I have never ever called a man daddy - not even the man that fathered me - he took off the day he learned my mother was pregnant.
I have nothing against men - its just I have never had a man to call daddy in my life.