North West and Penelope Disick Pose on the Red Carpet at JoJo Siwa's 16th Birthday Party

North West and Penelope Disick attend JoJo Siwa's Sweet 16 Birthday celebration at W Hollywood on April 09, 2019 in Hollywood, California.

North West and Penelope Disick are already pros at hitting the red carpet!

North West and Penelope Disick are already pros at hitting the red carpet.

The cousins and besties attended JoJo Siwa's Sweet 16 Birthday Celebration in West Hollywood, California, on Tuesday night, and struck adorable poses on the red carpet next to their idol. North, 5, and Penelope, 6, were joined by two friends, including Ryan Romulus -- the daughter of Tracy Nguyen Romulus, who is North's dad Kanye West's longtime publicist.

North and Penelope definitely dressed for the occasion. North rocked JoJo's signature big bow in her hair and paired the standout accessory with a glittery green jersey top, hot pink bicycle shorts, a fanny pack and silver boots, while Penelope also wore a bold look consisting of a rainbow sequin bomber jacket with matching pants and boots. 


It's no secret North is a big fan of JoJo. In February, North's mom, Kim Kardashian West, tweeted, "LOL @ North’s bow. She is obsessed with @itsjojosiwa." One month later, Kim revealed North got some one-on-one time with her idol. 

"North just FaceTimed @itsjojosiwa and her life is made!!!!!!" she tweeted. "That was the cutest thing ever seeing North soooo excited! Especially when she saw her dog bowbow."

North eventually collaborated with the former Dance Moms star on a video in which Kim drops off North so that JoJo can babysit her, and the two play hide-and-seek, make slime and check out JoJo's colorful car, among other activities.

At the 2019 Nickelodeon Kids’ Choice Awards last month, JoJo revealed to ET how the video came about. 

"It actually -- Kim reached out to me and I just responded to it," she shared. "So, me and Kim, we made some things happen together.... Super excited about it.”

Watch the video below for more: