There's an odd lack of words for friends you have sex with, but don't have a "relationship". Most terms imply a cohabiting long-term relationship, like partner. Or imply a challenge to such a long-term relationship, like mistress.
In Britain "sex friends" or "sex buddies" aren't popular terms yet. Though I think that they are the best around.
I could call myself a "swinger", after all I was a teen of 70s. But it seems some terribly dated and unnecessarily flighty. And polyamory sounds like something out of an anthropologists textbook. And in any case, the two are not quite the same: crudely, swinging is the sharing of partners between couples, polyamory is creating relationships that could be triads or quartets or larger.
But I live in a stable couple, though our sexual relationship, because of my husband's orientation, is the least important aspect of it. I don't really swing, except with my sister and my friend Lindsey. Though that's more of an coincidence (my sister's husband Robert and Lindsey's hubby Patrick are both bisexual, and get on well with my husband) then a deliberate aim. The core of those relationships is between me and Kate and me and Lindsey.
I do have sexual relations with lots of friends. Some are short-lived and intense. Some are long-lived and intermittent. Some are one night stands. Most are other women or girls, but there are several men.
So you see my problem, there isn't really a word to describe my sexy relations with my friends — assuming you ignore "slut" and similar boo words. Now I'm keen to reclaim slut as a sex-positive choice for women, just as homosexuals empowered themselves with gay, queen and queer. But it's still not a loving word. Actually, all the other boo words sound rather medieval: harlot, strumpet, trollop, hussy, Jezebel, doxy and now silly sounding unchaste. I rather fancy being a hussy myself, maybe because of its assonance with sassy.
So … me and some of my friends have sex, sometimes. And here are some
stories about them, a third real, two-thirds fiction (I don't know why so
many are fictional, there are plenty of real stories left untold). Accidents
happen…