(..why hello..! ) to vary the strokes, create and hold eye contact... encourage her to part her thighs and pout her cunt to allow things to caress her more fully.
To be bound like this and have my pussy flogged would give me an orgasm as well, and like the beautiful woman in this video the moans of pain turn to the pleasuring moans of orgasm along with the tightening and twitching of her body.