When two people meet eyes over and over again every day for an extended period of time, but they never say anything to one or another or discuss their feelings and desires. They are taking part in a silent relationship.
'Hot and shallow-acting football player' is sitting diagonally from 'pretty and down-to-earth dancer' in Chemistry class. Each time he casually glances at her, she feels his eyes scanning her's and looks up to meet him. They hold their gaze for as long as they can bare, then look away dramatically before anyone else can notice their silent relationship.
Outsider: Why don't you just talk to Him?
Silent Participant: If He likes me, he'll talk to me first. The guy is supposed to do the initiating, right?
Outsider: Um, not always. He's probably scared of you. You are a beautiful girl you know?
Silent Participant: Well, I'll just wait and see what happens...
(Nothing ever happens)
Outsider: You should've spoken to him before when you had the chance, dummy!
Silent Participant: I know, but I was scared. Now I'm going to go listen to Adele's "Someone Like You" and cry myself to sleep. Goodnight.