Is wearing Lycra a bit gay...?

I was wondering about 'straight'. I use it as a vaguely derogatory term on occasion, without meaning to refer to sexuality. Was 'straight' in the sexuality sense coined by the gay community? And was this much later than its existence as a term to describe either non-drug users or those without a shred of alternativeness (alternativity?) about them?

Good point

As a reaction to 'bent'?