Pregnant Sisters Khloé Kardashian and Kylie Jenner Pose Together at Christmas Eve Party

Pregnant Khloé Kardashian shared photo proof that sister and fellow mom-to-be Kylie Jenner was indeed at their momager Kris Jenner‘s annual Christmas Eve party.

On Tuesday, two days after the bash, Khloé, who confirmed that she and NBA boyfriend Tristan Thompson are expecting their first child together, shared photo booth shots of her and Kylie, who covered up in a leather jacket.

Sources told PEOPLE back in September that Khloé, who is nearly six months pregnant, and Kylie are due around the same time.

While Khloé, 33, and siblings Kourtney Kardashian, Kim Kardashian West and Kendall Jenner posted plenty of memories from the Christmas Eve party with fans and followers, Kylie — who is expecting her first child, a baby girl, with rapper boyfriend Travis Scott — did not appear in any photos from the bash shared to social media. But a source told PEOPLE she was there celebrating away from the cameras.

Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.

For more coverage, follow our babies magazine on Flipboard.

“Kylie looked great but didn’t really draw any attention to her baby bump,” the source said. “She still acts like she wants to keep her pregnancy private.”

Adding, “Everyone had the most amazing time. Kris always throws the best parties. It was all gorgeous. There was no drama.”

On Christmas morning, all the family members, including brother Rob Kardashian, gathered at Kourtney’s house to open presents and celebrate the holiday in matching elf-patterned onesies and beanies.

“She’s a secret little bunny,” Khloé teased.

“We created them. It’s our baby together, we have eight!” Kardashian proudly told Jenner, who responded: “We have so many babies, who knew?”

The sisters are all currently expecting — Kim will welcome her third child, a daughter, via surrogate — and an insider previously told PEOPLE they’re all prepping for their new additions.

“Khloé and Kylie are both starting to plan out their nurseries, and Kim and Kourtney are also involved in the process,” said the insider. “All the sisters are super excited, and Kris has been helping as well.”