Kourtney Kardashian definitely knows how to party.
The 36-year-old Keeping Up With the Kardashians star celebrated the upcoming birthdays of her two sons, Mason Disick and Reign Disick, on Saturday, as rumors around her and longtime family friend, Justin Bieber, continue to swirl.
The alien-themed outdoor birthday bash -- complete with a screening of Home, a bounce house and laser tag -- took place at Khloe Kardashian's house, and from what we've seen on their family's social media posts, it looks like things got a little weird.
See the evolution of the Kardashian-Jenner clan:
The evolution of the Kardashian/Jenner clan
Kourtney Kardashian celebrates sons' birthdays with alien laser tag amid Justin Bieber rumors
With his son Burt on his shoulders, American former professional athlete Bruce Jenner walks around the dirt race course during a break in the First Off-Road Championship Grand Prix in the Los Angeles Memorial Coliseum, Los Angeles, California, June 24, 1979. (Photo by Bob Riha, Jr./Getty Images)
LOS ANGELES - 1991: (Middle row, L-R) Brody Jenner, Kourtney Kardashian, Bruce Jenner, Kris Jenner, Cassandra Jenner, Kim Kardashian, (top row, L-R) Brandon Jenner, Burton Jenner,(bottom row, L-R) Robert Kardashian, Jr., Khloe Kardashian of the celebrity Jenner and Kardashian families featured in the TV show 'Keeping Up With The Kardashians' pose for a family portrait in 1991 in Los Angeles, California . (Photo by Maureen Donaldson/Michael Ochs Archives/Getty Images)
LOS ANGELES - 1993: (clockwise from top left) Burton Jenner, Khloe Kardashian, Bruce Jenner, Kris Jenner, Kim Kardashian, Brandon Jenner, Brody Jenner, Kourtney Kardashian, Robert Kardashian, Jr. and Cassandra Jenner of the celebrity Jenner and Kardashian families featured in the TV show 'Keeping Up With The Kardashians' pose for a family portrait in 1993 in Los Angeles, California . (Photo by Maureen Donaldson/Michael Ochs Archives/Getty Images)
Bruce Jenner, Kendall Jenner and Kris Kardashian during World Premiere of 'Mulan' at Hollywood Bowl in Hollywood, California, United States. (Photo by Ron Galella, Ltd./WireImage)
HOLLYWOOD, CA - DECEMBER 10: Bruce Jenner, Kris Jenner, Kendall Jenner and Kylie Jenner attend the world premiere of 'The Emperor's New Groove' on December 10, 2000 at the El Capitan Theater in Hollywood, California. (Photo by Ron Galella, Ltd./WireImage)
Bruce Jenner and wife Kris with daughters Kylie and Kendall (Photo by Cesare Bonazza/WireImage)
LOS ANGELES - JULY 29: Musician Brandon Jenner performs with his band Big Dume at Best Buy West Los Angeles on July 29, 2005 in Los Angeles, California. (Photo by Amanda Edwards/Getty Images)
LOS ANGELES, CA - OCTOBER 10: Kris Jenner, Kourtney Kardashian, Kim Kardashian and Khloe Kardashian attend Nick Cannon's Birthday celebration and opening of the PNB Nation store on October 10, 2006 in Los Angeles, California. (Photo by Chad Buchanan/Getty Images)
Kylie Jenner, Kim Kardashian and Kendall Jenner (Photo by Jeff Vespa/WireImage)
LOS ANGELES, CA - SEPTEMBER 25: Scott Disick (L) and TV personality Kourtney Kardashian attend 'Rock The Vote' Hosted by Christina Aguilera held at the Esquire House Hollywood Hills on September 25, 2008 in Los Angeles, California. (Photo by Frazer Harrison/Getty Images for Esquire )
LAS VEGAS, NV - SEPTEMBER 21: (L-R) TV personalities Kendall Jenner, Khloe Kardashian, Kourtney Kardashian and Kylie Jenner attend the iHeartRadio Music Festival at the MGM Grand Garden Arena on September 21, 2013 in Las Vegas, Nevada. (Photo by David Becker/Getty Images for Clear Channel)
LOS ANGELES, CA - APRIL 05: Musicians Brandon Jenner (L) and Leah Felder attend the 2nd Light Up The Blues Concert - An Evening Of Music To Benefit Autism Speaks at The Theatre At Ace Hotel on April 5, 2014 in Los Angeles, California. (Photo by Imeh Akpanudosen/Getty Images for LUTB)
LOS ANGELES, CA - APRIL 23: TV personalities Scott Disick (L) and Kourtney Kardashian attend Opening Ceremony and Calvin Klein Jeans' celebration launch of the #mycalvins Denim Series with special guest Kendall Jenner at Chateau Marmont on April 23, 2015 in Los Angeles, California. (Photo by Chris Weeks/Getty Images for Calvin Klein)
LOS ANGELES, CA - APRIL 23: TV personalities Kris Jenner (L) and Kourtney Kardashian attend Opening Ceremony and Calvin Klein Jeans' celebration launch of the #mycalvins Denim Series with special guest Kendall Jenner at Chateau Marmont on April 23, 2015 in Los Angeles, California. (Photo by John Sciulli/Getty Images for Calvin Klein)
NEW YORK, NY - JUNE 17: Kendall Jenner attends the 2015 Fragrance Foundation Awards at Alice Tully Hall at Lincoln Center on June 17, 2015 in New York City. (Photo by Michael Loccisano/Getty Images for Fragrance Foundation)
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"Alien laser tag," Kourtney captioned a group photo from the night, followed by with a close-up shot of some of the decorations.
Kourtney's youngest child, Reign Disick, turns one on Dec. 14 and made appearances in posts from two of his aunts, Kendall and Kylie Jenner. Reign shares his birthday with his older brother Mason, who will be turning 5.
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Kourtney's youngest child, Reign Disick, turns one on Dec. 14 and made appearances in posts from two of his aunts.
"Me as a mom," Kendall jokingly captioned her photo, which was re-grammed by her mom, Kris Jenner.
A source told ET that Kim Kardashian and her newborn, Saint West, were absent from the party, but her husband, Kanye West, and 2-year-old daughter, North West, were both in attendance, along with Kourtney's on-again, off-again boyfriend and father of her three children, Scott Disick. Kourtney and Scott are also parents to 3-year-old daughter, Penelope Disick.
Earlier this week, Kourtney partied with Justin in West Hollywood, California. A source told ET that the two were "nearly inseparable" on Friday night, as they were spotted together inside The Nice Guy. Justin gave an impromptu performance on the piano at the swanky celebrity hot spot, which seems to be a favorite for both Justin and Kourtney, as they were also spotted there together in October.
Their recent outings together have sparked romance rumors, including reports that the two are hooking up and that Justin is reportedly bragging about it to his friends. Kourtney and Justin have yet to comment.