A term for someone who should have come out a long time ago, who is now (and will always be) just awkward. People who are "GPED" can be of any age or gender, the "expiration date" is different for everyone. It's refers more specifically to the general sense of awkwardness some people have, not their age or situation in life.
Armando is a nice enough guy, but I wouldn't date someone who's Gay Past the Expiration Date.