With my first two or three girlfriends I always loved sliding a finger or two inside them so I could feel their vaginal contractions when they had an orgasm through clit stimulation (like tongue, fingers, or vibrator). But the last couple of girls I've been with I couldn't feel their orgasmic contractions at all. Now, I recently just realized with my current g/f that if I just insert one or two knuckles while stimulating her clit I can feel just the muscles right around the opening contracting when she cums. So I'm wondering if I just am remembering incorrectly that I had my fingers way inside and could feel the contractions there, or what. How deep inside the vagina (i mean, with fingers) can you feel the muscles squeezing? And do vaginal contractions happen in all women during orgasm, or just some? At first I thought all girls did, then I started to think that only a handful do and I was lucky the first few times. I even thought that these girls werent'really having orgasms even though they said they were, but all the other signs were there so I'm pretty sure they were.

Also, do other people get off on feeling/seeing it? When I found some porn that featured this I thought I'd found porn nirvana. It's the only porn I care to watch anymore.