What should I call my sub?

Me (26m) and my wife (24f) are starting to get into BDSM and she keeps asking me to give her a name. I’ve been into kink/bdsm for a bit longer than she but it’s taken some time for her to open up, I don’t want to rush into my fantasies and scare her out of the bedroom. She doesn’t want to be called the usual cliché (slave,slut,etc) but I was trying to think of something less aggressive but still humiliatingly sexy? I don’t know how to say it lmao but any help or suggestions would be greatly appreciated!!