UST

UST = Unresolved Sexual Tension 

Refers to the presence of an unrealised sexual relationship, but in which the characters react (either unawares or purposefully) to their desire for each other. Differs from subtext in that the attraction is not merely a perceived interpretation by fans but an actual factor influencing the canon and characters. Originated in The X-Files fandom, but has since been procured by several other fandoms as well.