Name calling...

When is name calling ever okay? So I'm not a morning person and need coffee and a little bit of time before anything else. Yet my SO thinks it's okay to call me an asshole if he thinks I'm acting like an asshole. We've been together for 4 years so it's not like he doesn't know about my need for my morning time. I've asked him to stop the name calling but he says if I'm acting like an asshole, he's going to tell me that. And there is no changing his mind - which leads into fighting the rest of the day. It just makes me feel small...and most of the time I feel like he just takes me the wrong way because I'm not ready to be carrying on a full conversation yet. Can I not just have that little bit of time to myself? And do I have to be an asshole because of it?