I’ve heard of this happening to some newlyweds via FOAF type stories. Is it for real? Are some women’s vaginal muscles really this strong?
This condition, called vaginismus should be your starting point for research.
Should be:
In close to 40 years of practicing ob/gyn, I have never seen or heard of this phenomenon occurring in human males/ females…
Yes and it’s not a bad thing. 
If a woman’s really nervous (vaginismus, etc…) the man’s not going to get in in the first place, unless he’s an asshole and doesn’t stop after the whimpering and “ow, it hurts” starts. The tightening is anticipatory, and it can be difficult to get a pinky in. In extreme cases, a q-tip can cause pain.
Dogs do it - it is called ‘dog knotting’
- quite worrying to watch
I don’t mean any offence, but there’s something about this post that appeals to my sense of the absurd. I can’t help imagining your research consisting of the sequential attempted insertion of a whole range of objects.
Mathochist: “OK, how about a zucchini?”
Female Assistant: “Ow! It hurts!”
M: “Well, that’s obviously not going in. Maybe the TV remote?”
FA: “Bloody ow! No way!”
M: “Hmmm… What about a Q Tip?”
FA: <grimace> “Nope”
M: <looks around the room hopefully>
To watch and to experience. 
Ever try to hold on to a greasy weenie? :rolleyes:
Yeah but what about the teeth
Teeth? I don’t have the time to give you an anatomy lesson and I’m probably not allowed to link to the ping pong ball crushing home vidio I have without getting banned from the board. BTW, her name was Kim . . .
And lest we forget the caterpillars…
They may look like caterpillars, but they are actually centipedes.
Is there actually a ‘clamping’ component to this? I had thought all of the plugging effect was caused by the male’s anatomy.
Okay, academic mode on:
Research consisted of a literature search consequent to a series of unsuccessful experiments involving one young woman very early in the experimenter’s career. Consulting at a later date with a more experienced researcher (the next young woman) indicated that certain of the experimenter’s own traits may have exacerbated the problems.
Happy?
centipedes? it’s more likely than you think!
Correct, it’s due to the knot at the base of the dog’s penis, which swells inside the female and keeps them together until he’s done with his business of making the next generation. Just be glad humans don’t have one of those, because then you’d have to make smalltalk!
The theory here, IIRC, is that the bulbospongiosi, which are muscles at the fronht of the vagina arranged in a ring-like shape, might occasionally spasm and clamp down hard enough to pinch off blood flow at the base of the penis, acting like one of those infamous “penis rings” that prevent blood from draining out of the corpora cavernosa, maintaining an erection artificially. As long as this goes on, the erection doesn’t go away, so the penis is trapped.
There are numerous reports of it happening, and they all say it’s excruciating for the man and woman both; something like a massive ongoing cramp or charlie horse for the woman, and like a bad case of priapism for the man.
However, there are also plenty of skeptics who make a convincing case that, unlike dogs, people just aren’t built in a way that allows it to happen to us. Color me skeptical … but then again, I didn’t believe the candiru would actually leap up into your urethra and crawl up your penis, and now we have a documented case complete with photos and video, and the testimony of both the surgeon and the patient. So hey, I guess it might be proven someday…