But their appearance together at a charity boxing event dealt those stories a killer blow.
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Pippa was on knockout form as she arrived with her 31-year-old love, their hands entwined.
The 28-year-old brunette had clearly gone the extra mile to dress up for her man with a plunging gown in striking red, golden clutch and matching stilettos.
It certainly had the desired effect – the pair were spotted kissing passionately at 4.30am following the Boodles Boxing Ball.
They were joined at the glam sports event by several members of the young royal set, including Princess Beatrice and her boyfriend Dave Clarke, Princess Eugenie and Chelsy Davy (below left).
Prince Harry's ex is reported to be seeing Jamie Richards, the 29-year-old son of Aston Martin boss David Richards. She arrived at the London event solo, however.
Prince William's former love Jecca Craig (above right) also attended, beautiful in a hot red gown very similar to Pippa's.
The future King's close friends, Hugh and Rose Van Cutsem – whose daughter Grace was a bridesmaid at the royal wedding – were also there.
It may not seem like the most romantic setting, but the sports event has long been a favourite 'date night' activity for the royal set.
The Duke and Duchess of Cambridge were spotted there in 2008, the same year Will's little brother enjoyed a night out with Chelsy.