Uggh! Look i know some people love the s&m action - but it ruins a punt for me when a wg unbidden asks for some rough stuff.
Thankfully it is only happened to me 3 times - 2 instances of "spank me hard, i'm your naughty girl" and 1 shocking "bite my tits" demand.
Really? I think it improves the punt.
Depends what it is obviously (I had a civvie ex who liked being choked - no chance, too dangerous and it made me feel like a serial killer) but spanking \ rough handling \ light hair pulling etc I will generally oblige them. The better the time they are having generally speaking the better time they will be giving me.
While it's not my job to make them come (that's THEIR job on me) its generally a bonus if you can make the WG have an orgasm \ good time, and it can yield a better punt \ better results \ more open to non-standard services in the future...