Never cross the RATP (Paris' CTA), they are ruthless.
Justine and I took advantage of the Journees du Patrimoine (This weekend, buildings owned by the French state not normally accessible to the public were open) by visiting the Chateau de Vincennes, built by Charles V of France, from 1340-1410. Well, King Charlie didn't build it himself, but you know what I mean.
On the way back into the city, I had to buy another set of metro tickets. Instead of waiting in line, Justine suggested I just follow her in through the turnstall, because it was a Sunday, and no one would be watching, and her friends do it all the time.
Of course, as soon as we passed through, we were approached by a stern-faced RATP employee who wanted to know what in the world we thought we were doing. Justine went into the famous French pleading mode I read about in Polly Platt (which normally works like a charm on men, she insists), but this woman would not budge. Even when Justine begged her to "look at me, like a human being". Zero tolerance. Stone cold. 50 euro fine.
Justine insisted on paying, so I just feel horrible. That was the most expensive metro ride ever.