It's New Orleans slang, babies. The song as a whole is about a regular corporate type of guy who once had an unforgettable experience with a beautiful Creole hooker. In the chorus ("Gitchie, gitchie yaya, dada, gitchie, gitchie yaya hee") she calls to him on the street, "Get your mocha-chocolate (referring to her skin) yaya (sex) here, daddy." The French ("Voulez-vous coucher avec moi ce soir") means, "Would you like to go to bed with me tonight."