A friend of mine recently went home with a young woman after a party. However, before he, you know, got down to business, he went to use her toilet and spotted Britney Spears's perfume in her bathroom. He promptly made his excuses and left. Was that unreasonable? And what are other similar style deal-breakers?

— Question sent in to the advice column Ask Hadley, in the Guardian. Hadley's answer may be deduced from the column's title, Why possession of a celebrity perfume is reasonable grounds to end a relationship.