Please excuse me as I'll be a tad fussy. You're welcome to pay me back in my own coin with my approximative English. The right expression is la porte arrière (

Please excuse me as I'll be a tad fussy. You're welcome to pay me back in my own coin with my approximative English. The right expression is la porte arrière (not "en arrière"), which usually means the back door of a vehicle. Some will more correctly say la portière arrière. It will rarely endorse the other meaning of "back door". Out of context, absolutely no one would see anything sexual in this expression. On the other hand, la porte de derrière will point to the door which is on the back side, for instance the back door of a house. In some contexts, it may convey some sexual innuendo.