You don’t want to bump into your mother-in-law on the landing wearing a threadbare Megadeth T-shirt and boxers. Paul Smith, Ralph Lauren and Calvin Klein all do smart sleepwear at prices that won’t keep you awake at night. But if you can, splash out on Derek Rose’s new slim-fit Bari pyjamas (£188, above). The game-changer is the self-seeking magnetic fly, designed so you won’t unwittingly shock anyone at breakfast. I’d still recommend button-fly boxers to doubly insure against embarrassment. That would be the wrong kind of splashing out.