The Kardashian-Jenner clan was out in full force for Cosmopolitan magazine's 50th birthday celebration in West Hollywood

By Lindsay Kimble
Updated October 13, 2015 08:20 AM
Credit: Jordan Strauss/Invision/AP

Just days after having to relive her emotional split from longtime partner Scott Disick, Kourtney Kardashian looked better than ever as she joined her famous family at Cosmopolitan‘s 50th birthday bash.

Kourtney hit the West Hollywood party with mother Kris Jenner and sisters Kim Kardashian West, Khloé Kardashian and Kylie Jenner – who all grace the cover of the magazine’s November issue. Notably absent: model sister Kendall Jenner.

The celebration, held Monday night at Ysabel, included a slew of other stars and a special cake.

Kris, 59, arrived first, starting the family’s brigade of black ensembles. She wore a long-sleeve black jumpsuit with wide-leg pants. Kourtney, 36, picked a similar look but sans sleeves. Kim, 34, opted for one of her usual tight-fitting maternity dresses, this time paired with a statement choker. Khlo , 31, donned a deep v-neck long-sleeve top and embellished velvet black skirt with a thigh-high slit. Youngest Kylie, 18, broke up the family’s theme in an off-white skirt and sweater.

Inside the party, the women clung close to each other, with Kourtney and Kylie at one point making a joint trip to the ladies’ room while gossiping, a source tells PEOPLE.

Kris Jenner Is Furious with Scott Disick

Kourtney, who emotionally detailed the demise of her relationship with Disick on the Keeping Up with the Kardashians season 10 finale on Sunday, got a show of support from her family on social media after Monday’s event.

“My little @kourtneykardash just warms my soul, Khloe wrote on Instagram, which Kris reposted, adding the sentiment “#unconditionallove.”

The first full promo for the upcoming season of KUWTK promises even more drama for the former couple. In one clip, Disick wipes away tears while sitting down with not only Kourtney, but also Kim, Kris and Khlo , as they confront him over his headline-making behavior.