Please don't judge...

So I have learned more about myself sexually. I am interested into kinkier things like sexual pain and bondage. Not to the extreme but I haven't found my limit bc I have not been that far with my boyfriend. I had my hands tied one time but that was it. But I want to do more and I don't know how to tell my boyfriend without scareing him. I just want to make it more pleasurable for both of us....please help.