Situational homosexuality

Women engaging in lesbian activities only because there are no men around, or not fuckable men, anyway. NOTE: Not all women-only worlds are situationally lesbian; some are created to show how really cool it is to be queer. Here's a clue: If the men show up to an only-woman world and the women want to fuck them, then they're situational lesbians. If the men show up and the women say buzz off, then they're real dykes.

• Pamela Kettle. The Day of the Women (1969) (lesbian attractions are hinted at, and disparaged, in Britain after the women take over)
• Charles Eric Maine. Alph (also published as: World Without Men). A loathsome sexist nasty book.
• Merril Mushroom, Daughters of Khaton (1987). Men show up on an all-woman planet. One woman was interested in a casual way in one of the guys before he turned out to be an asshole. Really, this is lesbian-feminist with openness to bisexuality; but it's relevant.
• Teresa Plowright. Dreams of an Unseen Planet (1986) (situational lesbianism b/w 2 women?)
• Susan Weston. The Children of the Light (1987) (In a post-apocalyptic alternative world, a young man becomes involved with a young woman ... who later gets involved with another young woman, much to the young man's surprise, disgust, and anger.)
• Molleen Zanger. The Year Seven. Includes situational lesbianism and real dykes; sexist men & nice guys (although not many of either, obviously).