If you have previously recommended this thread, you should see a tick / check mark on the recommend button. Click the tick to undo the recommendation (the tick may appear to change to a cross as you do this.) If you added a comment with your recommendation, you will need to delete that from your facebook wall separately.
It shouldn't be wet and it shouldn't be cold. It will probably be warm and may be windy.
I live in the Languedoc and the weather can vary a bit from area to area. In the autumn and spring you get the Vent d'Autan, a very strong but warm wind that gathers speed as it reaches the sea. It can last 1, 3, 6 or 9 days and it can drive you a bit nuts! By May it should have stopped although it's not a guarantee. Also there are some hilly/mountainous areas which are much cooler than the valleys so it may depend on exactly where you are going (sorry I don't recognise the name).
We went to the Languedoc in early June once - had a boat on the Canal du Midi and it was hot and sunny. We went to Lac des Reves at the beginning of July a couple of years back and it was not that crowded then, so I would think you would have no trouble in May. It is a lovely site, with lots to do in the near vicinity.