Struggling with S&M? You made me snort coffee into my lungs! When I think of S&M, I think of being tied up in ropes and "struggling" against the ropes, so it just hit me as hilarious!
In that case, I've been "struggling" with it, too! Only, safely.
And, the wheel isn't called a pain machine to anyone in the lifestyle, just the person writing the article. It's just something (like furniture) you can tie someone on and if they are NOT tied by the neck to the ceiling (dumb idea!!!) you can turn the wheel and they can be upside down.
I've hung people from the ceiling lots of times - by their ARMS. By the neck is just totally irresponsible. More than that, it's proof she's dumb as a stump and dangerously so. I'd never allow someone to do that in my presence.
Anyone who has ever enjoyed a little slap and tickle in the bedroom is into S&M. Did you not know tickling is a subtle form of sadism?
It's a spectrum of interests. It can be something as simple as a sharp nibble on the neck or as freakish as ... well, you can imagine.
Masters and Johnson did a study to find out what "normal" sex was, and do you know they came to the conclusion that there was NO such thing. Nope. What people are fed by their parents and society as what normal sex is (missionary, just for procreation, or whatever) isn't really the norm at all.
(Thank GOD.)
I like 
