“You do look very beautiful today – seriously,” he told her.
The dazzled best man, 26, voiced the nation's thoughts as he led Kate's radiant chief bridesmaid back up the aisle after their siblings' vows, reports the Sun.
Later the pair seemed to make a perfect couple themselves, as they stood side-by-side on the balcony of Buckingham Palace gazing down on the ecstatic crowds.
It also got many tongues wagging with suggestions that the pair looked such a good match that they might be the next royal romance.
Incidentally, Harry's on and off flame Chelsy Davy was also there.
Prince Harry switched on to his flirty best when he leaned over to whisper to his new sister-in-law Pippa Middleton about how beautiful she looked at the royal wedding.
Former England cricket captain Michael Vaughan jokingly took to Twitter to urge: "Make a move this afternoon, Harry."
Comedienne Katy Brand wrote: "Harry and Pippa whispering dirty, flirty little asides to each other."
Unluckily for Harry, she is seeing former England cricketer Alex Loudon.
Kate's naked nightmare
Kate Middleton is having a recurring nightmare - that she is nude in front of the marriage congregation, a media report said Wednesday.
Kate's sister 27-year-old Pippa, who is to be the maid of honour Friday, is in fits of hysterics, The Sun reported.
The 29-year-old has confessed to imagining herself in the buff as the world watches her tie the knot with Prince William.
Kate had suffered a similar anxiety-related dream in 2006 when she was about to start a new job at a clothing chain.
"Kate has the last-minute jitters and just wants the day to arrive. It's hardly surprising considering the stage she is going to be on - with the eyes of the world on her," a royal source was quoted as saying.
"But her nerves have manifested in an interesting way. A recurring dream she hadn't had for years has raised its head again."
In her nightmare, Kate finds herself nude in front of the congregation and then becomes suddenly aware she is stark naked.
The source said: "There is a deathly silence - and everyone from the Queen to Prince Philip is staring at her... Kate has joked the worst bit is she can't work out which parts to cover."
Kate's sister 27-year-old Pippa, who is to be the maid of honour Friday, is in fits of hysterics, The Sun reported.
The 29-year-old has confessed to imagining herself in the buff as the world watches her tie the knot with Prince William.
Kate had suffered a similar anxiety-related dream in 2006 when she was about to start a new job at a clothing chain.
"Kate has the last-minute jitters and just wants the day to arrive. It's hardly surprising considering the stage she is going to be on - with the eyes of the world on her," a royal source was quoted as saying.
"But her nerves have manifested in an interesting way. A recurring dream she hadn't had for years has raised its head again."
In her nightmare, Kate finds herself nude in front of the congregation and then becomes suddenly aware she is stark naked.
The source said: "There is a deathly silence - and everyone from the Queen to Prince Philip is staring at her... Kate has joked the worst bit is she can't work out which parts to cover."
