“Man of Steel, Woman of Kleenex” is an essay in which science fiction author Larry Niven, author of Ringworld, details the problems that Superman would face in having sexual intercourse and reproducing with “a human woman designated LL for convenience”, using arguments based on humorous (yet logical) reconciliation between physics, biology. The firm basis for this essay being the abilities of Kryptonians as presented in Superman comic books.
It was first printed in Niven’s 1971 collection, All the Myriad Ways.
In 1986, the essay was reposted onto Usenet; this led to what is thought to be the very first online report of copyright violation.
This is a link to the original, but it is not for those of faint-hearts.