Kate Middleton may have let the sex of her unborn child slip today as she greeted well-wishers in Grimsby, England. As the Telegraph reports, the duchess was chit-chatting with fans when one woman handed her a teddy bear. Kate reportedly replied, "Thank you, I’ll take that for my d..." then stopped herself.

According to Us Weekly, another bystander asked her if she had meant to say "daughter," to which the royal replied, "We're not telling." Not telling or don't know? Because another bystander heard her say, "No, we don't know." The plot thickens...

Either way, this is exciting because we can finally start envisioning how amazing it would be if Kate and Will had a girl. No offense to baby boys, but think of the fashion potential!

In addition to inheriting a great sense of style, Catherine's baby girl would also inherit the throne. This year, the British parliament moved forward with legislation to end the principle of male primogeniture, so that Kate and William's first child regardless of gender. Yes, Kate's first born might one day become queen.

But we probably won't know the baby's sex for a while. The British royal family's longstanding tradition is to not announce the sex of the baby until after the birth. Instead, a note is put on the gates of Buckingham Palace that announced the child's arrival, thus revealing the details to the world.