Thomas Michel Mustin ( born 21 November 1990), known professionally as Mustii , is a Belgian singer , songwriter, writer , actor and director . He is known for his roles in theatre, television and Netflix productions, including the popular feature films Grave, Un Petit Boulot and L'Echange des Princesses, as well as the Belgian series La Trêve. He will represent Belgium in the Eurovision Song Contest 2024 with the song "Before the Party's Over" .