Originally Posted by
orbitmic
Don’t do it - way too much less for very little rewards and your bp will most likely not work when you come back from the city and try to clear security again so you’ll waste time both when trying to exit the terminal and when trying to re-enter. Not worth it.
Sure, but it all depends on how long the layover is and how badly OP wants to see Paris. If it is a layover of 8-10 hours.....then the 1.5 hours RER return plus 2 hours entering and leaving the airport may be worth it. Did something similar during a long stop in Shanghai which was ok - and a next time I felt more like sitting it out relaxing in some snooze corner. BP may not work for a 2nd time entering the lounge (although I would say AF should not care about this - OP will in fact spent less time in the lounge overall if heading for Paris), but I never experienced problems in leaving & entering an airport in such situations (one ticket, all BPs printed, leaving the airport for some hotel or city visit during a long layover).