I have to say it's her reaction. wrinkled eyebrows, gasps, her wetness running down her leg...
I get off on just pulling hair- it's the same thing. sliding my hand up her neck, grabbing deeply against her scalp and squeezing my hand shut as I pull her head back- the look on her face as she trembles is awesome...

now, that kissing my palms first....THAT's a nice idea.....