I know someone who fits your description a hell of alot - in front of teachers or something he'll always go "aww man this question/topic is gay!" - and gets the same, dirty look all the time. Then he always has to explain to them that "he obviously isn't calling the question homosexual - its just annoying him". This seems to be EXACTLY the kind of translation people put it to today - By todays standards, "gay" = 'unhip', 'annoying' or generally 'not on'.

"Stop being gay!" - Stop annoying me
"This is so gay" - I am so 'not' enjoying myself
"This weather is gay" - It's not MY type of weather

I wonder how long it'll last.