Anyone else here had experience of this rather frightening problem? It only happened to me once. ISTR the correct term is vaginismus or something similar.
It was the first time that she and I had had penetrative sex. She'd never experienced enjoyable sex before (she'd previously been married to someone she didn't love ... don't ask), and it was the first time she'd had an orgasm. Her vagina went into a tight spasm, gripping my cock as hard as your hand can squeeze, which of course made de-tumescence impossible; it's kind of an impasse thing, a Mexican stand-off, and nobody's going anywhere. Thoughts of "how can we get to the phone to call an ambulance" go through your mind, and "what will her neighbours say". I mean, how are they going to carry the two of you out to the ambulance, or do you walk, pretending to be doing a very, very passionate dance? It's times like these one both thanks and curses the gods for endowing one with a long willy.
Thankfully, 15 minutes of lying still and thinking of raindrops on roses, whiskers on kittens etc allowed thing to relax enough for extraction. But wow, it was scary for a while (but in these somewhat less rigid times, nice to remember).
Anyone else been there?