World’s First 4-D Sex Tape! (At Least We Think Someone Is Having Sex Here)

April 16, 2008
DASHIELL

Mary Roach's "Bonk" (not to be confused with this or this) takes a look at the research of sexual physiology--in other words, what's really going on with our bodies when we fuck, and believe it or not no one really knows for sure. From Leonardo Da Vinci's "coital interlocking" theory to the frustrated egg breakers of today, lots of people have tried and failed to figure out exactly how Bolt A fits into Slot B. The latest attempt involves 4-D ultrasound movies that can look inside us in real time, and it also involves Mary and her husband, who became the first sexual guinea pigs to be filmed internally while getting it on. She can explain the whole thing better in the video below, and though it may seem a little dry we promise you'll be rewarded with some hot 4-D porn if you watch the whole thing. (Unfortunately, like most ultrasounds, you still need a doctor to tell you where the penis is. Still!)