Princess Diana's parents might have been happy when they finally welcomed a baby boy, but that moment of joy was hardly enough to save their marriage. As a result, the ill-matched couple began living separate lives. Unfortunately, though, this meant that Diana and her young brother, Charles Spencer, 9th Earl Spencer, got caught in the middle of their parents' drama.

According to the Channel 5 documentary "Diana: The Curse of The Spencers," the trouble started when Frances Shand Kydd met Peter Shand Kydd. The pair got along well, and over time, their relationship became romantic. Eventually, Frances decided to leave Althorp House and relocate to London, where she could be with her lover. Her two youngest moved with her.

Sadly, that wasn't the end of the drama for the brother and sister duo. During the Christmas of 1967, Frances thought that it would be nice for the whole family to reunite for the holiday. In the end, though, this decision represented a tense miscalculation on her part. Once the festivities were over, the children's father, Johnny Spencer, 8th Earl Spencer, refused to let Charles and Diana go home with their mother. Reflecting on this moment, royal reporter Angela Levin said in the documentary, "I think Johnny did it out of spite."