I wrote a nice long response but than the internet ate it
The cliff notes version:
I'm a pretty decisive and opinionated while still being submissive. I can be that way because:
1. If he didn't want my opinion he wouldn't ask for it.
2. Lying, including lies of omission results in serious punishment. It's mutually beneficial for us to be honest with each other. He can't fully control me without knowing how I feel and that includes any pre existing issues like sore feet. It's his decision whether or not I experience pain or pleasure (this bit is at the core of the issue for me).
3. I know that giving my opinion doesn't mean it's my decision. When I give my opinion it isn't always followed.
4. There are things that one of us is indifferent about and it's understood that the one that cares can make the decision.
5. There are things we disagree on and we work out a mutually satisfying arrangement.
6. We discuss every new thing at least twice, once right afterward and once later on after we've digested the experience.
In any case lying isn't something that's ok to let go. If self sacrifice is a need for him, by all means indulge it on your terms.
Example
"Would you like to go for a walk?"
"Yes mistress but my feet are sore."
"Alright you can come" and you make it shorter if you like or "No stay home and get better"