Our marriage is a fairy-tale marriage,” William H. Macy once said of his relationship with Felicity Huffman. But friends of the couple, who have been married since 1997, fear they might not live happily ever after in the wake of the college admissions cheating scandal. After making a deal with the feds, the Desperate Housewife, 56, agreed to plead guilty to paying $15,000 to have eldest daughter Sophia’s SAT scores doctored, with prosecutors recommending that she serve four months behind bars and pay $20,000 in fines. But instead of spending what little time they have left before her sentencing together, Felicity and William, 69, have been spending more and more time apart. In fact, the pair haven’t been photographed together since April 5! “The scandal has put such a strain…