Sentence:  Now if it&#39;s true, as I believe, that every woman has a bit of a lesbian streak, or at least curiosity, then it follows that the ideal way to satisfy it is with <WSD>troilism</WSD> — making love with two girls and a man. I&#39;ve tried it myself and I know. ... 
Meaning of the word marked with <WSD> tags:  The practice of three people having sex, i.e. having threesomes.