how do I bring up the kinky stuff I want

okay so me and my boyfriend have been together for a year and a half now and the sex is great, like the man knows what he doing with his dick 👌🏻 I'm very much a sub and I like it super rough and he'll choke me and pull my hair and he loves it when i tell him to take control but I think he's afraid to hurt me. I want to get /more/ kinky though like I want him to tie me up to his bed so i cant move and blindfold me and spank me and bite me and leave marks on me and call me degrading names and stuff but I don't know how to bring it up or if he'd even be into it, any advice would be greatly appreciated!