You have to earn the right to be called Daddy.

I’d go a step further and say no one has a right at all to be called Daddy.  It’s not your decision.

Honestly, while I stand behind the basic Idea, in this sort of gendered context I’m not comfortable with the transactional implications behind the word “earned.”  Because, for instance, imagine someone demanding “I’ve done X for you, I’ve done Y for you, I think I’ve earned the right to Z you.”  That would be flat creepy.  In fact in even the most benign context it still perpetuates the gender stereotype that men provide and women decide.

Consider an assertion you occasionally see on dating sites: “I’m a MILF.”  Or, more rarely, “I’m a DILF.”  You don’t get to decide if you’re a mom or dad someone else would like to fuck.  Similarly you don’t get to decide someone else should call you Daddy, or Sir.  Or, for that matter, you don’t get to decide someone else should call you Babygirl.

It’s ok to say “I’m a Daddy.”  I say that all the time.  That just designates my particular category of kink, like saying “I’m a Submissive” or I’m a rope top.”  But unless and until your partner makes the call you don’t get to say “I’m your Daddy.”