Robbie Williams has jokingly addressed a "deeply unprofessional" on-screen gaffe during the World Cup final in which he accidentally spat a small white object onto his microphone. Robbie Williams performed alongside Nicole Scherzinger and Laura Pausini at the World Cup closing ceremony (Bradley Collyer/PA Wire)The incident quickly garnered attention. Williams later took to social media to share a video explaining the mysterious item, clarifying the nature of the unexpected moment. Williams stuck the object on his forehead after it dropped onto his microphone (Magenta Sport)Williams breaks out laughing before the video cuts off. On Sunday night, the first World Cup half-time show was also held.