I just realized the story is in L'Equipe today, I hadn't seen it in the middle of an article about the duchess of Kent:
He had lost a bet. He had told Julie during their last match than if he was going to be broken, he would dress up for their next match. And of course he was broken.
The supervisor ("the sheriff") didn't let him play like that on Sunday and he had to change his outfit.
You should really post it in the "Funny pics" thread!
(Edit: I posted it since you have the URL and the watermark on it and I can't find other pics of it, I hope you don't mind, it's a good promotion for your site.)