Prince Charles had a cruel trick he would play on Princess Diana to fool her into thinking he was home when he was really seeing Camilla, a royal author has claimed.
Journalist Andrew Morton has claimed that the heir would circle TV shows in the Radio Times to lull his wife into believing he was planning on staying in when he was having an affair.
The royal biography author said he still gets a "shiver down his spine" when he thinks back to the things Diana candidly told him in a series of secret interviews.
