More Adventurous Sex

So my boyfriend is the only guy I've been with and is also my first relationship. He's older than me and has more under his belt if you catch my drift (he's older than me as well) So I really want to have more adventurous sex- tying up, spanking stuff like that. But he doesn't want to try that because he said he doesn't want to open my mind to "sexual deviant-ness" How do I make him do more in the bedroom? I don't want to pressure him or make him uncomfortable but I want to do it. I know he's done stuff like it in the pass because we've had open dialogue about his past relationships and sex. Any tips?