How do I stop calling my stepdad dad?

Just stop saying it, yes I will do that, but how to not make it awkward and confront any questions that I get from him.

Oh yeah just for context I started calling him dad a few years back but never felt good thinking of him like that as we barely speak, he is a decent guy though. Just wanna start calling him by his name but it just feels like by doing so some problems will arise. Just need tips on how to handle it all really. I’m not sure.