"Man of Steel, Woman of Kleenex" is a 1971 essay in which science fiction author Larry Niven details the problems that Superman would face in sexual intercourse and reproducing with "a human woman designated LL for convenience," using arguments based on humorous reconciliation between physics, biology, and the abilities of Kryptonians as presented in Superman comic books.
A comic book-style adaptation—illustrated by classic Superman artist Curt Swan, and with all identifying logos and names removed—was published in a 1995 edition of Penthouse Comix.
Fun Fact: In
1986, the essay was reposted onto Usenet; this led to what is thought
to be the very first online report of copyright violation.
Fun Fact: Many of the points given in this essay are reused and paraphrased in Kevin Smith's 1995 movie Mallrats.
Fun Fact: Tom Smith's "Superman Sex-Life Boogie" recounts the problem from Superman's perspective.
Fun Fact: The 2012 graphic novel Superman: Earth One, Volume Two has Jonathan Kent trying to warn an awkward teenage Clark about sex, saying "Man of Steel, Woman of Kleenex. That's all I'm saying."