(Note: Mistress Matisse is away this week, so here's a classic Control Tower. Matisse will return next week. —Eds)

I was sitting at a party with a friend recently when she asked me, a bit shyly, about CBT. She didn't mean computer-based training, or cognitive-based therapy. What she meant was cock-and-ball torture.

"I'd like to try a little bit," she said. "But I don't want to really hurt him."

It was similar to what I often hear from people new to what I call genital sensation play. People are intimidated by the word "torture," but in fact, we're not talking about illegal interrogation techniques here. This is just good, clean, kinky fun.

"Why would anyone want to do that?" For starters, even non-BDSM men do wacky things with their dicks in the quest for new sensation: vacuum hoses, apple pies, sheep. Not every guy, of course, but if you question an honest man long enough, odds are you'll uncover some story about his cock and something other than his hand or someone else's body.

And cocks are amazingly resilient, despite their sensitivity. That piece of flesh has to ensure the survival of the species, and yet it's dangling free, liable to get clawed by saber-toothed tigers or stomped on by woolly mammoths. I myself have done some very severe things to boys' bits, and they were perfectly fine and functional afterward, in spite of all that sissy wailing.

I'm teasing. The wailing is part of the fun. But even if you don't want your boy screeching, there are safe, easy things to do that won't damage his wedding tackle. A good way to start is a little simple impact sensation.

To start off, get ahold of your boy's dick before he's hard. When the cock is hard, the contents—blood vessels and chambers and the tissue itself—are all under pressure. The tension in the flesh makes the sensations more intense, obviously, but it also creates a situation where you're more likely to get a bruise or lingering soreness. I've never seen anyone die from a bruised cock, but I think starting with it soft is a better idea.

Now, support it from underneath with one hand, and with the other, just give it a little slap. Not too hard—the kind of slap you'd use to kill a mosquito on a baby's body. Do that a couple of times and let him get used to the idea. Then slap it again, a tiny bit harder, and after you do, squeeze it gently with the supporting hand. Let your fingers caress a little bit. Then slap it again. Then caress it again.

By mingling the intense sensations with the more pleasurable ones, you can get away with a lot, and if everybody's happy with the scene, you can ramp up the intensity of the slaps fairly high without fear of serious damage. And one final thought: All breezy humor aside, genital sensation play can be emotionally intense. Go slow, keep in touch with your partner, and make sure the experience you create for him is a positive one.