To solve this, first complete the Riley riddle as a clue to the real question, asked below.
Clue:
My prefix can be pumped or eaten
My suffix is a French saint.
My infix could be a famous French region,
but just in the movies by name.
Question:
What have you already done when you are offered a free ride?
Hint:
Isn't it...?
Hint 2:
The clue doesn't refer to a french word, despite how _____ that is.