Flakes

flake ^(flāk)

Is this word used in the straight world, or are the quality of gay men so poor that it has to be applied to the gay vocabulary?  I used this word to describe a friend whom I had planned to hang out with.  During the conversation, my friend who was not a flake asked: “Flake?… what does that even mean”.  (This friend I should point out is straight)

I felt embarrassed that I had to explain that a flake was someone who makes plans and disappears.  Someone who makes plans but never has the common decency to cancel.

Is it just gay people?  Or is it everyone?