My bf is vanilla but he’s interested in the lifestyle. I have the experience to teach him but I’m a sub. how do I educate him without affecting the power balance or offending him?
First, good on you for wanting to teach him what you know and for him wanting to learn!
Does he want you to teach him what you know? If so, then you won’t offend him and it likely won’t disrupt the power balance. Everyone who has ever taught someone something knows that once the teaching is over the balance goes right back to where it was. As long as you treat him with respect and give your information and knowledge from a place of intelligence and sharing you’ll be fine. However, if you treat him like a child or you boss him around (“That’s not how you do it, move over and let me show you!”) he will quickly be turned off by not only you showing him but perhaps learning about the lifestyle at all.
You can also suggest reading certain passages, books or websites on his own time that will help his learning increase without your direct input. The local BDSM community in your area is another wealth of information that he might enjoy.
I know that you are concerned with disrupting your place as a sub in this situation, but as long as you keep in mind that you are the sub and you are serving his needs by teaching him what you know then you will still remain in the submissive mindset. It’s all about a mental shift, a hard one, but definitely doable in a teaching situation.
I've written about how to use your knowledge and experience as a teaching tool for your Dominant before so go check that out too!
Good luck and have fun showing him the ropes!