The interrogation scene from Basic Instinct is one of the most famous in modern movie history. However, the truth behind the way the scene was shot changes the situation quite a bit. We all know the scene at this point. Sharon Stone is being interrogated by cops, including Michael Douglas, when she throws all the men off their game by uncrossing, and then recrossing her legs, revealing the underwear that she doesn't have on. In the shot, the men mostly become slobbering idiots trying to get a good look, but the truth is they didn't see anything, because they weren't in the room.
According to director Paul Verhoeven in Empire magazine, the scene was actually filmed in two parts. The scene where Sharon Stone did her thing was filmed without any of the actors in the room. All of their reactions to her were filmed prior to the actual shot, which was left to near the end of filming at Stone's request. The scene with Sharon Stone was filmed with no other cast and minimal crew. The director said they did two or three takes of the shot from two different angles, and that was it.
While it isn't too surprising to learn that the men weren't in the scene, as it was an incredibly private thing to do on film, the fact that the men were actually shot first is a little surprising. It would seem that they were only told what it was they were reacting to, leaving the entire thing up to the imagination. It's hard to say if that makes the whole thing better, or even more creepy.
The scene wasn't in the original script for Basic Instinct. Instead, Paul Verhoeven says that he was inspired to add it during filming following a meeting at a party in the Netherlands in the 1960s. He met a woman who also apparently didn't wear underwear, and, apparently due to the effect that she had on the men at the event, the director realized that Catherine Tramell could do something similar with the cops. You can watch the scene below, but it goes without saying this is NSFW.
Paul Verhoeven also discusses the fact that for a long time Sharon Stone claimed she'd been misled to film the scene, something the director denies and the actress has apparently become more philosophical about the experience. He says there was really no way he could have filmed what he did without her fully understanding what his intentions were.
Almost 25 years later we still have not forgotten that particular scene from Basic Instinct. It's unlikely that we ever will.