On Friday night, Kourtney took her daughterPenelope, 6½, and Kim’s daughterNorth, 5½, to anAriana Grandeconcert at The Forum in Inglewood, California.
Grande is currently embarking on herSweetenerworld tour, which will next head to Las Vegas for a Saturday night show.
In photos from the night shared to her Instagram Story, Kourtney (whodressed up as the pop star for Halloweenlast fall!) shared footage of Grande singing her song “R.E.M.”
The 40-year-old reality star also shared a sweet photo of cousins Penelope and North posing on a bench, captioning the image “past our bedtime.”
Kourtney Kardashian/Instagram


The Kardashian family is known for being big fans of Grande — besides Kourtney’s tribute Halloween costume, momKris Jennereven starred in the music video for Grande’s song“thank u, next.”
The concert outing came only hours after Kim, 38, announced on Twitter that she and West had welcomed their fourth child, a son, via surrogate.
“He’s here and he’s perfect!” Kardashian West tweeted, following up minutes laterwith a second postthat read, “He’s also Chicago’s twin lol I’m sure he will change a lotbut now he looks just like her.”
Kim Kardashian West and Kanye West with their children.Kim Kardashian/Instagram

Along with quite the brood — her three children (Penelope,Reign Aston, 4, andMason Dash, 9) plus Kim’s children North,Chicago, 15 months, andSaint, 3 — Kourtney brought the news that Kardashian West’s surrogate would be giving birth shortly, explaining why her sister wasn’t on the show as planned.
“What! What are we doing here?!” said Jenner visibly shocked, adding, “For how long?”
“And nobody knows, so everyone in the audience don’t tell,” Kourtney explained while laughing.
“Kim and Kanye were both present for the hospital birth on Thursday,” an insidertold PEOPLE on Friday. “They are ecstatic. Their little boy is super cute and looks like Kim.”
source: people.com