Until courting couples learn this rule, girls will go on ending up with drawersful of unwearable slippery camisoles in lurid colours, and men with racks of acutely embarrassing ties.

• 互献殷勤的男女们直到后来才了解这个规则，结果是女孩们的衣橱抽屉塞满了难以捉摸的、不能穿着的色彩艳丽的贴身内衣，男人们则有了一排排令人极度尴尬的领带。