Does Prince Harry have a real secret?
The Royal is set to reveal one of his secrets today as part of a campaign to help reduce stigma associated with HIV.
But what is it? Twitter has been set abuzz with guesses.
Some were cruel. And pretty unoriginal.
Some would cause a real storm:
Some were light hearted.
But the campaign, which is on World AIDS Day has a serious point. The 30-year-old said in an introductory video: "Globally, HIV is the second-highest cause of death amongst those aged between 10-19 years old, and it is the number one cause of death across Africa.
"One tragic issue in particular is the shame and stigma linked to HIV.
"This causes thousands of children to needlessly die each year because they're keeping their illness a secret and not getting the medical attention they need."
The royal will be joined by stars including Nicole Scherzinger, Gemma Arterton and Paloma Faith, who will all lay their secrets bare to the world on video in support of Sentebale's #FeelNoShame campaign.
Harry co-founded his Sentebale organisation in Lesotho two years after travelling around the country in 2004 and seeing for himself the problems faced by Aids orphans, disabled children and others with serious issues.
The campaign aims to raise awareness of how eradicating shame and stigma can save the lives of HIV sufferers, empowering them to seek medical support and education about their condition, and preventing the virus from spreading.
Lesotho has the third highest HIV/Aids prevalence in the world after Swaziland and Botswana.
More than 37,000 of Lesotho's 500,000 children are HIV positive and approximately 200,000 have lost parents to Aids, forcing them out of school and into hazardous forms of labour including prostitution and trafficking.
Since 1996, the country's average life expectancy has fallen from 59 years to below 48.7 years.