Okay, nobody is going to get it.
One of JK Rowling's heroes is Jessica Mitford - but Rowling thinks considerably less of her sisters, Diana and Unity Mitford. Diana and Unity were Nazi sympathisers; Jessica was not. They are represented in the books by three cousins: Bellatrix, Narcissa and Andromeda Black. Bellatrix and Narcissa joined Voldemort's cause. Andromeda became a member of the Order of the Phoenix, fighting him. The one we are focusing on is Narcissa Black, who represents Diana Mitford. In the world of the books, Narcissa Black married Lucius Malfoy, and produced a son, Draco. In the same way, Diana Mitford married Oswald Mosley, and produced a son of her own - Max. Since the Malfoy parents are directly based on Oswald and Diana, this means that Draco Malfoy and Max Mosley are one and the same.