OT3

Etymology
coined by analogy with.

Noun

 * 1)  One true threesome; a polyamorous  involving three characters that is a personal favorite of a fan.
 * 2) * 2017, Charity A. Fowler, "Negotiating Desire: Resisting, Reimagining and Reinscribing Normalized Sexuality and Gender in Fan Fiction", dissertation submitted to Virginia Commonwealth University, page 286:
 * For some, each member of the triangle cares deeply for the other two, like Elena/Damon/Stefan and Scott/Allison/Isaac—both the most popular OT3s in their respective fandoms.
 * For some, each member of the triangle cares deeply for the other two, like Elena/Damon/Stefan and Scott/Allison/Isaac—both the most popular OT3s in their respective fandoms.