On Saturday night at the Parc des Princes, Kylian Mbappé was in a good mood. Not because his team, Paris Saint-Germain, were struggling to score without him against Lorient in their Ligue 1 opening game of the 2023-24 season. Not because one of his best friends in football, Ousmane Dembélé, was sat next to him in his box. No: most of all, Mbappé was happy because he knew that his…