Communication isn’t magic, it’s the pan you bake a cake in… it shapes and supports a relationship, and without it, the whole thing collapses into goo. It’s absolutely essential. But there’s a lot more to “happy birthday” than slapping a spring-form on the kitchen counter.
As for starting the talk, that depends on which one you mean… the “oops, I’m kinky and you’re not” talk, the “we’re both kinky but you’re really bad at it” talk, the “if I admit what I’m into I’m afraid you’ll run screaming from the room” talk, or what? I’m missing important data.
With that said, in general, the most productive way to start a talk is to be ready to listen… explain as simply as you can that there’s something you need or something that’s troubling you, and give them the room to tell you how they feel about that. Making your point shouldn’t be your primary agenda… your message will be best received by someone who feels that your focus is on understanding him.
Good luck.