All of the third generation Kardashian children are in the 2015 Kardashian Christmas card -- except for the family’s newest edition, Saint West. The holiday greeting features sister North West, 2, and his cousins: Penelope, 3; Mason, 6; and Reign Disick, 1. But why was little Saint left out?

One of the reasons is because the infant, who was born Dec. 5, isn’t old enough. “Saint is too young and they have other plans on the reveal,” an insider told Hollywood Life in an exclusive interview Wednesday.

Unlike previous years, none of the adults in the family are featured in the Christmas card. “They all thought showing the next generation was the way to go because they love the fact that it is all about the future. Nobody in the family is thinking backwards, they are all thinking of the great things they expect for the future,” the source told Hollywood Life.

But there might be a more simple explanation: The busy family simply couldn’t find the time to get together. "This year, especially the last couple months, was so hectic that it was hard to arrange a full family shoot. Showing the kids alone seemed like the perfect thing to do,” an insider told E! Online Wednesday.

It’s the first Kardashian Christmas card since 2013. The family didn’t put our their annual greeting last year because they “ran out of time,” but it also should be noted that Kardashian "momager" Kris and Caitlyn Jenner were in the process of finalizing their divorce.

This time around, all the Kardashian sisters shared the third generation holiday photo. Kylie and Kendall Jenner noticeably did not post the picture on social media. The Kardashian sisters also added the caption, “All you need is love.”

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