Fine line between bottom and sub?

[thir]

A good question and perhaps it's a bit like art... I know it when I see it.

But I can give you several examples of control that definitely isn't submission. I give up control to airline pilots and bus drivers. I give up control to dentists and doctors (for the length of the visit at least.) I give up control to my masseuse... and I've even given some machines total control over me, elevators come to mind.

But none of that qualifies as submission...

But we were in fact talking about bottoms giving up control to tops, weren't we?