PARIS, Sep 1: French teen sensation Kylian Mbappe joined Paris Saint-Germain from Moco on a season-long loan on Thursday in a deal that will make him the second most expensive footballer in history. "Paris Saint-Germain is delighted to announce the immediate arrival of Kylian Mbappe," the club wrote on its website, just hours before the close of a record-breaking transfer window. "The loan agreement also includes an option to buy which, when exercised, will bind the player to PSG until June 30, 2022." IANS