It is a paternity suit that not even DNA testing can solve. A five-year-old boy may never know his father's identity because his mother claims she had sex with identical twins at the time he was conceived. Lawyers admit that the most advanced genetic testing techniques are unlikely to prove which of the twin brothers - in their late twenties - fathered the child. The unprecedented case in Montreal, Canada, is a real-life rerun of a plot twist in Zadie Smith's 2000 novel White Teeth, in which the character Irie Jones has sex with the Iqbal twins on the same...