A felt‑tip sign taped to the door of a private room announces "GIRLS ONLY", "Boy's don't Eneter!" [sic], and, by way of a cheeky flourish, "don't worry boys!". The sign is covered in colourful hearts and stars. A group of around a dozen girls at DRMZ youth club in Carmarthen, Wales, are already deep into a competitive card game when I join them at a large round table.