Cory won't admit this to anyone, but he still thinks Shawn made the hottest girl ever. Not hotter than Topanga, of course, but definitely enough to pose a threat.
It doesn't even make sense. Shawn isn't made of manly muscles, but as long as Cory's known him he's never even looked remotely feminine. So how did he almost forget the hot little redhead who called herself Veronica was his friend, let alone that he was in on it the whole plan?
It's the pouty lips, he decides. The sexy, pouty lips.
Of course, it doesn't hurt that Shawn himself is amazingly hot-no, I did not just think that! Shawn is a guy, Shawn's his best friend, Shawn is better-looking than him but he's not hot. Not to Cory.
It's perfectly normal to pleasure yourself in the shower thinking about your hot best friend in drag!
"...oh, fuzznuts!"
He has a girlfriend, he's been into girls for as long as he can remember. So what is it about Shawn? It isn't even a matter of "he's my best friend", even if Shawn was a total stranger he'd be hot. But Cory's not gay, not even bi.
Shawn's the exception, I guess.