More detail on the fictitious "venus butterfly".
The supposed sexual technique was introduced on the Thanksgiving episode of LA Law in 1986. LA Law, for those who don't remember it, was a popular and generally enjoyable paint-by-numbers legal drama of the 1980s.
In the November 21, 1986 episode, a schlumpy defense attorney named Stuart Markowitz (played by Michael Tucker) visits a polygamist whom he is defending, in prison. The man had been married 11 times and never divorced (almost unimaginable given the marital contortions of the characters in LA Law). Stuart asks what the man's secret is for keeping women happy, and the polygamist whispers the answer to him, so the audience can not hear it.
Cut to a scene with Stuart and the more attractive lawyer Ann Kelsey (Tucker's real-life wife Jill Eikenberry) in bed. They've just finished getting it on, and as Eikenberry described the scene for TV Guide,
I said, 'Oh my god, what was that?' and I went on and on about it. He said, 'The Venus Butterfly.' So I said, 'Could we possibly do it again?' And then, he picked up the phone for room service... and the scene ends. So we think it has something to do with room service!
The next morning, all the drive-time DJs were talking about it, and it became water-cooler conversation for a couple of weeks. Cecil Adams fielded a question about it. Penthouse claimed to know the secret. It had become a meme, in all the ways a televised idea could become one in the days before the web. The producers got a lot of mail about the episode, some angry that they would broadcast such smut, but most wanting to know the secret technique.
Another segment on that night's show involved a distraught mother searching for a body that might be the corpse of her kidnapped son, getting to the morgue only after great bureaucratic hassles, and discovering that they had already cremated the body. A third involved a squabble over the office of a departed colleague. Finally, Susan Dey and Harry Hamlin were involved in a murder case in which they believed the accused man to be guilty but justified in killing his ailing wife.
Many sex books today claim to teach the "Venus Butterfly" technique and a variety of sex toys are named after it, but none of these are connected with LA Law, and the writers of that program have never revealed the secret (making clear, in fact, that there is no secret to reveal).
LA Law dominated the dramatic series awards in the Emmys that year, and the Venus Butterfly episode in particular won Steven Bochco and Terry Louise Fisher the award for Outstanding Writing in a Drama Series.
Michael Tucker has been married to Jill Eikenberry in real life for 29 years, and according to the Internet Movie Database, they have worked together 11 times since LA Law. According to Tucker,
After the show, we went off to discover what the Venus Butterfly is, and we're still working on it. It's a lifetime proposition.
People Magazine, February 2, 1987