My ex doesn’t like me saying his name?

Me and my ex are cool and have the understanding of being friends. But often times he doesn’t like it when I call him by his first name. (Which everyone calls him). I usually call my friends ‘bruh or bro’ but he seems irritated when I call him that. I reassure him that it’s okay to call me by my first name. But he always say ‘mamas’ or just not my name at all which is uncomfortable. How should I address this?
My ex doesn’t like me saying his name?
Post Opinion