Twin gays are gay male or lesbian couples that basically look identical to each other, both in looks, clothing, etc., implying that their homosexuality is essentially an intense obsession to have sex with yourself.

Adj. Something that is expected to have a long lifespan by virtue of having existed for a long time, based on the lindy effect, named for the New York restaurant Lindy's, coined by Albert Goldman and popularized by Nassim Taleb.