A/N: Another one of those midnight plot bunnies...lol. Enjoy!
Disclaimer: I don't own Psych.
Ambivalence (n): a state of conflicting emotions at the same time related to the same object, idea, or person.
It is, of course, Gus who realizes it first. The time he spends playing referee between Shawn and Lassiter is enough that he learns their tells; the smallest of unchecked reactions which would, under normal circumstances, be ignored. But Gus spends too much time watching them and he comes to know which expression or gesture means what.
It's all there, in the way Shawn tilts his head and the volume of Lassiter's growl. It isn't long before Gus begins to wonder why no one else can see it. Then he wonders if maybe they can but they choose to ignore it.
Henry realizes it next, after his fishing trip with Lassiter. The young detective doesn't realize, but he lets a few things slip. And, of course, Henry picks up on them. He taught Shawn everything he knows, after all.
When Shawn comes up in conversation, he immediately notices the way Lassiter speaks. Not the words so much as the tone and the inflection. Because while Lassiter may be discussing what a nuisance Shawn is, Henry can tell there's something more.
Chief Vick doesn't bother with passive observation. At the first inkling of suspicion, she calls Lassiter into her office and asks him straight out.
"Detective Lassiter, is there something going on between you and Mr. Spencer?"
"No, Chief. Why would you think that?"
She doesn't answer, just tells him he can go. Because she isn't convinced. She can tell there's something more.
Juliet is the last to learn of it, because Lassiter doesn't really talk. She calls Shawn's cell, intending to ask his advice on a case, and it's Lassiter who answers. She quickly hangs up and checks and rechecks the number before accepting it.