Michael Quinion’s 1996 article How bona to vada your eek!, A gay way of speaking, is a good read. He describes two characters on the BBC’s Round The Horne radio show who played a pair of screamingly camp young men who spoke in an unusual “language” called Polari.
This was not a constructed language, but a secret vocabulary, a cant or argot in the linguist’s term, which uses the grammar and syntax of English as well as most of its core vocabulary. It was in fairly common use in the theatre and in related branches of show business such as ballet and the circus…
… Polari is a linguistic mongrel. Words from Romany (originally an Indian dialect), Shelta (the cant of the Irish tinkers), Yiddish, back slang, rhyming slang and other non-standard English are interspersed with words of Italian origin.
… perhaps you might like to be able to count to ten in Polari: una, duey, trey, quater, chinker, sey, setter, otto, nobber, dacha.
I love this stuff!