My wife had a friend at called Cathy Sex who, in turn, had a younger brother called Nicholas Sex. Makes sense really - it's a bit difficult otherwise.
My wife tried very hard to get Cathy involved with a bloke called David Sessions in the hope of a great double-barrelled name; Cathy's brother managed to glide through life without too much trouble except for one occasion when on a train. The guard asked him for his student rail card, looked at it and said, "I've been waiting all my working life for you!"