In this article, I will summarize some of the most standard methods for giving pain to a woman’s general crotch area and pussy, and a man’s cock and balls.
First let’s begin with activities that you can do with both. After listing them, I will then describe the recommended target area.
Biting,
slapping,
clothes pins. go for plastic over wood to avoid splinters),
candle wax. go for the appropriate temperature. Apparently Jewish Shabbat candles are perfect,
the Wartenberg wheel (it has a small handle and a small spikey wheel you can roll, it’s great for causing stinging pain without leaving marks)
electro shock device (various electro bdsm kits are out there, they attach to any spot you wish and you can send shocks)
Now as for where:
On the woman: slap the entire area, bite the lips (not the clit!), and the rest of the activities only perform on the outer lips and the surrounding area.
On the man: except for slapping (and obviously even then be careful) don’t do any of these on the balls themselves. On the cock and the ball sack, all activities are fair game.
In regards to sadistic fun on women’s pussies specifically, the main obvious one is particularly rough penetration, including strong thrusts, very thick dildos, and fisting. In addition there are toys that perform a constant suction vacuum to the pussy.
For the man specifically: there are devices that you can wrap around the ballsack above the balls and hang weights on them stretching the balls, there are sleeves with spikes that hurt more as the cock gets hard and expands, and finally as a particularly symbolic femdom activity there is kicking of the balls (obviously start light).
With all of these activities, make sure to follow Safe BDSM Practice . Use safe words, start light and gradually grow intensity. Stop if you see any blood (which has happened very occasionally but has always been benign) and keep an eye on the sub’s reactions.
As for prevalence, from my personal experience, both you and the women will be surprised by how many women like at least some pussy masochism. Up to two thirds, with about half of those maxing at a fairly light intensity.