Is Kate Middleton Having a Boy?
The Duchess of Cambridge arrives at Hope House addiction treatment center in south London, February 19, 2013. According to a report, Middleton is rumored to be pregnant with a boy. Reuters

Ever since the royal family announced Duchess Kate Middleton and Prince William were expecting last year, rumors have been rampant whether the newly married couple were expecting a boy or a girl.

The U.K. Mirror's Sunday People claims a royal family member may have prematurely slipped the gender of the newborn prior to its expected July arrival.

A source reportedly close to Prince Harry told the tabloid that he has been telling close friends that his sister-in-law is expecting a boy.

“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,” said the source, who claimed Middleton was thrilled to discover the child was male.

While Harry may have already revealed the child’s gender, the source said the couple isn't revealing the short list of names they've selected.

“They’re really working hard on baby names now and think they have it sorted but they won’t reveal anything to anyone -- not even Harry,” said the source. “Of course, Harry’s been making up crazy suggestions and winding them up too.”

Prince William’s cousin, Princess Eugenie, has also been telling friends that the baby is a boy. The source said that the couple's friends and family members have already inundated the expecting parents with blue-themed gifts.

“The close inner circle all know that it’s a boy and they’re busily buying fits with a boy theme. There will be an awful lot of blue in their house.”

Rumors that the Duchess was expecting a girl circulated in March after Middleton was allegedly caught saying the letter “D” after thanking a woman for a teddy bear gift.

“Thank you I will take that for my d… for my baby,” Middleton told the woman, according Sandra Cook, 67, of Grimsby, who was standing nearby.

“When she shook hands with me I said, ‘You nearly slipped up there, you were going to say daughter, weren’t you?’” said Cook, who claims the Duchess replied that the couple didn’t yet know the sex of the baby and weren't planning on revealing the gender. (Despite Harry's reported slip, the royal couple still haven't officially commented on the baby's gender.)

Us Weekly reported in March that the expected royal child was female and that the couple had been referring to her as “our little grape” and planned to pay homage to family members with the name Elizabeth Diana Carole.