Answer:
In Paris but not in France the thinnest of its siblings.
I am the kind of nut that is empty at the center and has no shell.
I go around in circles, but always straight ahead, never complain, no matter where I am led.
I am in the past never in the future. I don't exist but have existed. I saw what you saw and that is what I will ever see.
I am owned by every man though my length differs. Their wives uses me after getting married.
Some try to hide some try to cheat. But time will show we always will meet. Try as you might to guess my name. I promise you'll know when you I do claim.