Gays meaning has changed.
Gay used to mean lovely, delightful, gay, happy days.
Gay then meant literally as in. "Wooahh dude. Your gay."
Gay now means 'Thats pretty shit, But i cant swear in front of my grandma, So this'll do'
Grandma; We're off the church this morning!
Anti-Christ; Ohh gay
Grandma; =]