It's not uncommon for husbands to give up drinking alcohol in sympathy with their wives when a couple are expecting a child, and, if Kate really is pregnant, it seems the royal couple may be doing just that.
For, tonight, Kate and William drank a traditional champagne toast to the Queen with goblets filled with water, fuelling speculation that a royal pregnancy is upon us.
Of course, it could just be the tropical heat - but it is unheard of to drink a royal toast with water except for medical reasons.
Last night, Kate also made the royal toast with water while William opted for a glass of red, but tonight, at a banquet at Singapore's Eden Hall, they both drank water, grinning broadly at each other as they did so.
Earlier in the day, during a walkabout, William told a child who asked him a direct question that he would like to have two children.
A source told the Royalist that Kate was pregnant during the Olympics, but that the couple have decided to wait 'as long as possible' before announcing the news.
They will certainly want to wait at least three months, meaning an announcement could be several weeks away.
