Subgirrl why are you running away?
I have fisted to partners. Both of them really loved it. Both had similar experiences of coming pretty darn close to passing out because their orgasms were that intense. I was just talking about this topic to a lady friend of mine. If the lady is in to it, it can be a very pleasurable activity. It will and does take some time to learn how to fist. If I can give any advice it would be to make sure she is really aroused. Giver her some orgasms first. There will be no such thing as using too much lube. Wear a medical exam glove, latex or non, to protect her tender inside from scratches from your fingernails (and lube works well on the latex to make things easier to penetrate). Go slow! And I mean slow. Gentle steady pressure usually work. And by god you better be good at following her reactions to know when she is ready for more to enter, if it is causing her pain, you need to follow her lead. You may be doing the fisting, but she should be in control of this activity. Once you are in, give her pussy a bit of time to adjust to having your hand inside. Once she is ready.... then move your hand or your fingers or whatever she wants. Oh yeah. Hold on because she will be bucking all over the place if she is anything like the women I fisted.