An insider close to Harry told Sunday People: "Harry has been telling everyone Wills and Kate are having a boy and how thrilled he is at the prospect of having a little nephew. He said the whole family were excited about it. Apparently Kate has always wanted a boy."
"They're really working hard on baby names now and think they have it sorted," the insider said. "But they won't reveal anything to anyone -- not even Harry. Of course, Harry's been making up crazy suggestions and winding them up too.
"The close inner circle all know that it's a boy and they're busily buying gifts with a boy theme. There will be an awful lot of blue in their house," the insider told Sunday People.
Meanwhile, there has been no confirmation on the baby's sex from William or Middleton, Sunday People reported.