Erinja makes a good point. We use Esperanto at home and we do have some words and expressions that we know other Esperantists could not understand and we never talk that way in front of them. It has been one way for my husband to master E-grammar and have fun with it. It is our own little dialect.

Every Esperanto couple that is together for a long-ish period of time has their own private language and private expressions, to an extent. Sometimes it's based on languages that one of both of them speak, sometimes on personal experiences or whatever. I have always thought it would be interesting to ask many Esperanto couples about their private language and write an article about it, but I was too lazy to do it. However I have asked a number of couples and the answers are always interesting!