From Wikipedia
Leather Goddesses of Phobos is an interactive fiction computer game written by Steve Meretzky and published by Infocom in 1986. Like many other Infocom titles, it was released for the IBM PC (DOS), Atari 8-bit, Amiga, Apple II, Apple Macintosh, Atari ST and Commodore 64 computers. This game was Infocom's first "sex farce" and featured selectable "naughtiness" levels ranging from "tame" to "lewd". It was one of five top-selling Infocom titles to be re-released in Solid Gold versions including in-game hints. It is Infocom's twenty-first game.
The game begins in Upper Sandusky, Ohio, in 1936 and is presented in the manner of a science fiction serial of that time. The Leather Goddesses of Phobos are just finalising their plans for the invasion of Earth. The player's character has been abducted by the Leather Goddesses for the final testing of the plan which will enslave all of humanity. Unless this nefarious plan is stopped, the Earth will be turned into these twisted vixens' pleasure dome. Despite the player's possible motives, this outcome is considered unfavorable.