DEC's engineers nearly got a PDP-11 assembler that used the `SEX' mnemonic out the door at one time, but (for once) marketing wasn't asleep and forced a change. That wasn't the last time this happened, either. The author of "The Intel 8086 Primer", who was one of the original designers of the 8086, noted that there was originally a `SEX' instruction on that processor, too. He says that Intel management got cold feet and decreed that it be changed, and thus the instruction was renamed `CBW' and `CWD' (depending on what was being extended). Amusingly, the Intel 8048 (the microcontroller used in IBM PC keyboards) is also missing straight `SEX' but has logical-or and logical-and instructions `ORL' and `ANL'.
The Motorola 6809, used in the U.K.'s `Dragon 32' personal computer, actually had an official `SEX' instruction; the 6502 in the Apple II with which it competed did not. British hackers thought this made perfect mythic sense; after all, it was commonly observed, you could (on some theoretical level) have sex with a dragon, but you can't have sex with an apple.