There are a LOT of answers to this question…
First of all, if this is something he wants or needs, then you are not hurting him either emotionally or physically, you are filling a need. The best example I can think of is our children. There are all kinds of things we must do to and for our children that we don’t like/want to do, but if we are good parents we do them because it is what is best for them.
As for me, I must admit that I think there is a true streak or a bit of sadism in me. Fortunately for me I found a partner with which I can let it out and not feel confined. However for you, if it’s not in you, then it’s not in you. We tried for years to have my husband be the dominant, but that is just not who he is and it never really worked out.
We are who we are. We can try hard to do our best to adapt who we are to meet our partners needs, that’s compromise, but ultimately we have to ACCEPT each others limitations.
In your case I have suspicions… If your husband is trying to talk you into this, trying to negotiate, bargain, con, coerce… then it sounds like he might actually be topping from the bottom and that is not submissive behavior at all, that is controlling. If that is the case, he is NOT going to like it when he gets what he is asking for. He is not going to like true submission or service. The whole idea behind this lifestyle is that he meets YOUR needs. His needs are an after thought. If your needs are getting laundry done, doing the dishes and rubbing your feet, then that is what he is asking for.
My advice to you is sit down and both of you find out what each other is ASKING for. No hints, clues, assumptions, hopes, guesses… spell it out and then find common ground.
One of the things it sounds like he is asking for is for you to push his physical/emotional limits with pain/humiliation. Pushing limits is a good thing. It’s exercise. In him asking you to do that, he is also asking you to do that. It’s something you would be doing together.