Does this mean he's really submissive?

Not at all.  Many men like discipline and are not in the slightest bit submissive by nature. There is a big difference between being naturally submissive compared to him getting his bottom thrashed every now and again.  Neither should you assume this is a female led lifestyle described in other blogs. Many of the people, men and women, I have met who enjoyed discipline in their lives were strong confident characters and used to being in control.  In many cases, it is for that exact reason that they give up control for a small bit of their life to someone else.