So, for example, if I were to joke about you going to Eton I'd make fun of you going to a posh school. If it's not used jokingly then the word 'ponce' is often used. When people use the word 'posh' to describe something a school, a car it usually is with some affection or in a leg pulling way. In fact, I haven't heard this used in this fashionsince about the seventies.
But this day and age the use of the word 'ponce' to mean homozexual is rarely used.