One of the first Larry Niven stories/essays I can recall reading is now online (with permission from the author): Man of Steel, Woman of Kleenex. Here’s a sample:

What arouses Kal-El’s mating urge? Did kryptonian women carry some subtle mating cue at appropriate times of the year? Whatever it is, Lois Lane probably didn’t have it. We may speculate that she smells wrong, less like a kryptonian woman than like a terrestrial monkey. A mating between Superman and Lois Lane would feel like sodomy-and would be, of course, by church and common law.

It’s wickedly funny and all too true! Poor guy.