troilist

1. not comparableInvolving three sexual partners; pertaining to a threesome.

   She has a troilist marriage with two men in her home department in South America.

   1999, W Warren Wagar, A Short History of the Future, page 198

   2 more examples

   But, once they had properly got into their stride, the three singers whipped themselves up into a frenzy of sexual abandon, attaining heights of troilist ingenuity worthy of some erotomaniac Heath Robinson […]

   1992, Gilbert Adair, The Postmodernist Always Rings Twice

   They were both small, with the sort of dark-and-comely, fair-and-goodly features which could give Popes troilist fantasies – although nothing was in their minds much beyond flip-charts, language schemes, lip-patterns and audiograms.

   2010, Alan Richardson, On Winsley Hill, page 65

plural troilists

1. A participant in a sexual threesome.