A new biography delving in to Meghan Markle's life claims her ex-husband can still "barely contain his anger" over their breakup five years ago.
Ms Markle, now engaged to Prince Harry, divorced Hollywood producer Trevor Engelson in 2013 after two years' marriage.
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Royal biographer Andrew Morton, the author behind Diana: Her True Story, revealing the life of the late Princess Diana, has penned what allegedly went wrong.
"[Engelson] went from cherishing Meghan to, as one friend observed, 'Feeling like he was a piece of something stuck to the bottom of her shoe'," Mr Morton wrote.
"A wealthy entrepreneur friend claimed the marriage ended so abruptly that Meghan sent Trevor her diamond wedding and engagement rings back by registered mail."
Mr Morton also says sources told him Engelson "can barely contain his anger", adding it was "totally out of the blue".
"Whether she wanted to admit it to herself or not, Meghan, who once said she couldn't imagine life without Trevor by her side, was now building a new world for herself.
"She was her own woman now, earning a steady income, making new friends on-set and off, no longer dependent on her husband's connections."
The book, due for release on April 12, also details the soon-to-be royal's interest with Princess Diana.
"She was always fascinated by the royal family," her friend Ninaki Priddy told Mr Morton.
"She wants to be Princess Diana 2.0."
"Party animal" Ms Markle also apparently gained a lot of weight at college in Chicago, from carb-heavy food and late night trips to Burger King, Mr Morton writes.
Ms Markle and Prince Harry will be married in May. Bridebook expects it will be one of the top 10 most expensive weddings of all time.