Baby Over Birthday! Kendall Livid After Pregnant Sister Kylie Skips Party

The Keeping Up With the Kardashians clan was in full force to celebrate Kendall Jenner’s 22nd birthday at Petite Taqueria in West Hollywood, Calif., last night! And although the model’s estranged parents, Kris and Caitlyn, put their differences aside to be there for Kendall’s big night, RadarOnline.com has exclusively learned that her younger sister, Kylie, REFUSED to attend because she is not ready to reveal her baby bump! Click through 7 shocking party pictures to find out all the details inside the twisted sisters’ nasty spat!

As fans know, Kendall is dating NBA star Blake Griffin, 28. Perhaps that is why Kendall didn’t mind that sister Khloe, 33 — who is pregnant and lives in Cleveland, Ohio, with NBA player Tristan Thompson, 27 — couldn’t make the party! In addition, as RadarOnline.com previously reported, Khloe is also suffering from serious morning sickness.

The birthday bash turned into a Jenner family date night, as cougar Kris, 61, came with on-again, off-again boy toy, Corey Gamble!

For the first time since her Kardashian-bashing book came out, Caitlyn Jenner, 67, came face-to-face with Kris and her estranged family. And she brought her smoking hot 21-year-old trans gal pal Sophia Hutchins for good luck.

Kim Kardashian, 37, and Kanye West, 40, as well as sister Kourtney, 39, and boyfriend Younes Bendjima, 23, all came out to celebrate.

But according to a family insider, Kylie, 20, who is pregnant with her first baby from rapper boyfriend Travis Scott, 27, “refused” to show up to her sister’s big night and, needless to say, Kendall was furious! “She thinks Kylie is an idiot for not coming to her party. If the tables were turned, Kylie would throw a fit,” the source said.

“Kendall does not understand why Kylie is trying so hard to hide her pregnancy and that she chose to remaining in hiding over attending her birthday,” the source told RadarOnline.com. “Kendall is just glad that she isn’t the one with a baby on the way!”