In the past lingerie has had its moment; the underwear as outerwear trend became big news last year due to the emergence of Lady Gaga and her risqué outfits, which inspired many replicas on the catwalk, albeit not quite as daring. Corsets, negligés and silky underwear became the focus of many runway shows, sometimes worn with high-waisted harem trousers, other times paired with chiffon blouses. The dare to bare trend was proof that fashion is nothing if not unpredictable, and this season Stella McCartney was the leader of a new trend; pyjamas as eveningwear. McCartney's Spring/Summer 2012 collection took the traditional silk pyjama and dressed it up - with leg-lengthening heels and a sharp blazer pyjamas have never looked hotter. They're being tipped by fashion editors as the coolest trend of the season, and why not? They're low-maintenance, ridiculously comfortable and they demonstrate the nonchalant "I just threw this on" attitude that even the edgiest fashionistas try so hard to nail.