It is a Kurt/Karofsky future fic in which I think Karofsky sees Kurt, and before he knows who he is, he is thinking that Kurt is just his type.
But, when Karofsky recognizes Kurt, he thinks (or perhaps says to someone else) something to the effect of, "He's not just my type; he's the original model."
If anyone can track it down, you will have my eternal admiration. Thanks!
ETA: Found! Link in the comments!