According to reports, the Duke of Edinburgh also spoke to his grandson about his decision to marry an actress.
"One steps out with actresses, one doesn't marry them," Prince Philip is said to have told Prince Harry.
Prince William is also believed to have cautioned his brother which reportedly led to a falling out between the pair.
"William was quite concerned that the relationship had moved so quickly," royal expert Katie Nicholl told a TLC documentary.
"And being close to Harry, you know, probably the only person close enough to say to Harry 'this seems to be moving quickly, are you sure?
"And I think what was meant as well-intended brotherly advice just riled Harry."
It was also revealed earlier this year that Prince Harry cut off his good friend Tom Inskip after he advised him not to marry the former Suits star.
According to Tatler, the former 'Party Prince' banished his childhood mate from his inner circle.
Harry and Tom, a banker, had been friends for many years. In fact, Tom was with the now Duke of Sussex back in 2012 when he was busted playing naked billards with showgirls at a hotel suite in Las Vegas.
Harry also attended Tom's wedding in Jamaica in 2017.
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