Keep your shirt on in Narbonne

[Torchwatch]

I also like string and mesh T shirts, would I get fined in Narbonne?
I love my Aussibum white and ice blue nylon swim briefs, I would find a T shirt made from this fabric irresistible but if it gets wet it goes almost invisible. If I walk into Narbonne completely legally but get caught in a shower would I get fined?
I have some really nice leather shorts, they are quite short and have double front zips in the German style, if I were to get a matching leather chest harness could I promenade the streets of Narbonne without fear of being detained under the no shirts bye law?
I just remembered I have some Tom From Finland swim briefs, they are quite unsuitable to wear in a public family swimming pool. Looking on Ebay they have Tom From Finland tee shirts. I would look considerably less shocking to the public with no shirt than with one of these tee shirts, should I buy one just in case I visit Narbonne?