Now as you go at the G-spot you'll find that your woman keeps coming for longer than you've seen before. You may even experience that most startling of sexual phenomena, a female ejaculation. I've seen three of these (actually I got a mouthful), but I can't say whether the fluid comes from the vagina or the urethra. It's quite nice, sort of like salad dressing. It's definitely not urine, and it is probably polite and hopefully reciprocal to swallow it.

Keep going at that G-spot. Eventually you will feel the vagina draw away from your finger - it becomes bigger and the walls get taut, and not form-fitting, sort of like a little cave. When it does this it's time to switch back to the clitoris. Keep up the same rhythm. When the vagina begins to contract on your finger again, go back to the G-spot.

If you keep this up for a while (and if the owner of your female genitals wants to stop, then stop - this isn't a competition), you'll find that the nature of the vaginal contractions changes.