How to tell him

Struggling with how to tell my husband about a sex kink I really want to explore. I’ve fantasized about doing this particular thing for a very very long time, but over the last year or so I’ve desperately wanted to actually try it with him. It’s kinda a weird one and I’m afraid he’ll judge me or say no. How can I bring it up or even start the conversation? I’m so embarrassed I don’t even know if I could get the words out.