I may get into trouble for saying this but Ironwood recently told me:

"I take it as a compliment if a woman tries to kill me during sex."

And along with pulling a guys hair when he goes down on you and a few other things, nails down the back is all part of losing control because of the pleasure he's giving you, and that can't be a bad thing!

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'Don't knock masturbation - it's sex with someone you love'

- Woody Allen