pippa kate
Photo: Getty

Because the world is just a better place when there’s a royal wedding to get excited about, Princess Eugenie of York, daughter of Prince Andrew and Sarah Ferguson, is set to marry Jack Brooksbank on October 12 at St George’s Chapel in Windsor. It’s set to be a grand (and eco-friendly) affair suitably fit for a princess, and of course there’ll be a star studded guest list—but it seems as though there may be one empty seat next to Prince William. It’s thought that Kate Middleton may have to miss Eugenie’s special day, due to some fairly tricky schedule clashes involving Kate’s sister, Pippa, and a rather big baby bump.

Related article: Why Kate Middleton And Prince William Missed Charlie Van Straubenzee’s Wedding

According to the Express, the Duchess of Cambridge is currently an undecided guest for the princess’s upcoming wedding, as there’s a possibility that the nuptials could fall on the same day that Pippa Middleton is due to give birth. The sisters are famously close, and it seems obvious that Kate would want to be at Pippa’s side when her new niece or nephew is welcomed into the world.

kate pippa
Photo: Getty

But if you were looking forward to seeing Kate’s next wedding guest ensemble, or just new BFF photos of her and Meghan Markle together, don’t lose all hope just yet. Pippa’s exact due date isn’t publicly known, and this all just stems from some very logical guess work. A mention of the subject in her Waitrose column saw Pippa reveal that she had entered her second trimester of pregnancy, which would put the expected arrival of the newest Middleton in October some time. The chance of a schedule clash is probably slim, but not totally impossible.

Related article: Why Pippa Middleton’s Baby Will Not Inherit A Royal Title

Kate might not be able to make it, but you could always try your luck. Eugenie and Jack are following in the footsteps of Prince Harry and Meghan Markle and inviting 1,200 lucky members of the public to their wedding at Windsor Castle. You have to live in the U.K. to be considered, but you can find out how to apply here, and then prepare your fanciest hat.

Related article: Pippa Middleton Confirms Her Pregnancy In A New Fitness Column

This article originally appeared on Marie Claire