The relationship between Prince Charles and Princess Diana was complex and has been the subject of much public speculation and media coverage. It is known that Prince Charles had a close friendship with Camilla Parker Bowles, now the Duchess of Cornwall, both before and during his marriage to Diana. Their relationship continued to be a point of controversy and speculation during the course of their marriage.
The revelation of Prince Charles's affair with Camilla came to public attention much later, after the breakdown of his marriage to Diana. In a 1994 television interview, Prince Charles admitted to being unfaithful to Diana, but he also stated that he tried to be "faithful and honorable" during their marriage.
The emotions and expectations involved in such complex personal relationships can vary greatly from person to person, and it would be speculative to assert how Prince Charles expected Princess Diana to feel about the situation at the time. Their marriage and the events surrounding it were deeply private matters and are best understood through the perspectives shared by those directly involved or through reputable historical accounts.