What to call my boyfriend in bed?

Hi guys so my boyfriend and I have really gotten kinky in our relationship in a lot of different ways and we’re having a great time. He always refers to me as “slut” when we’re having sexy time and we both really like that, but we’re trying to figure out something to call him. I tried calling him “daddy” and he said he was perfectly fine with it but it didn’t particularly “get him going” or anything. He said he doesn’t like “sir” because it’s too formal and I feel like he’ll probably feel the same way about “master”? Idk, but what do you guys call your doms besides those three things? I told him I need something special to call him to help me get into kinky sexy mode and he’s willing to try things out until we get a good one! Help please!!!