EWINCHI

Everybody Wants it, Nobody Can Have it. The classic coming-of-age trope. (can be stylized EWI;NCHI)
Used when describing a steamin' hot hot hot girl or guy, who is either (likely) taken, or one of a dozen other reasons why you need not apply.

Reasons why someone could be an EWINCHI:
Hot girl/guy online going viral.
Literal celebrity.
Women online are not real.™
"He's the most popular guy in school!"
gay

Or anything that makes this person your equivalent to an MPDG.