"Ciel mon mari" is traditionally used in comic theatre when the woman is in bed with her lover. When her husband arrives at the door she cries "Ciel mon mari" (sky my husband) and quickly hide her lover in the wardrobe or on the balcony...
Have great fun Cyclefrance ! Just be careful when using popular expression.
There's also "argot" (slang), "verlan" (back slang) cf
The Alternative French Dictionary
verlan = "à l'envers (backward) / à lanver = verlan"
meuf (say mef) = femme = woman
keum (say kem) = mec = guy
laisse béton = laisse tomber = Let it drop!
In French suburbs, teenagers speak in verlan, it's quite difficult to understand them but they are very inventive.