Kylie Jenner may have been sporting a "Dirrty" midriff-baring costume last year, but she's staying covered this Halloween

Kylie Jenner may have been sporting a “Dirrty” midriff-baring costume last year, but she’s staying covered this Halloween.

While her sisters Kim Kardashian West and Kourtney Kardashian teamed up for Saturday’s pre-holiday festivities, dressing as Madonna and Michael Jackson to recreate the famous looks of the King and Queen of Pop at the 1991 Academy Awards, the 20-year-old reality star kept things chill over the weekend.

Kylie — who is expecting her first child, a girl, with rapper boyfriend Travis Scott — opted for Snapchat’s puppy filter over a costume on Sunday, snapping a selfie with mom Kris Jenner. She wore a simple black sweater, also on display in a selfie video taken in her car.

Credit: Kylie Jenner/Instagram

The makeup mogul also spent the weekend promoting new shades of Kylie Cosmetics Lip Color, which are launching on Tuesday.

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Credit: Kylie Jenner/Instagram

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But Kylie hasn’t missed out on all the Halloween fun this year. Earlier this month, she stepped out for a special double date with her boyfriend, sister Kendall Jenner and Kendall’s beau Blake Griffin.

An onlooker confirms to PEOPLE that Kendall, 21, and Kylie spent a Sunday evening at Universal Studios’ Halloween Horror Nights in Hollywood, California. The foursome was also joined by Jordyn Woods and Hailey Baldwin.

“Kylie and Kendall were both extremely loving and cuddly with their boyfriends,” the onlooker told PEOPLE. “Both couples had their arms around each other, and the girls were really sweet with their guys. Travis and Kylie were especially cute and lovey-dovey. Kendall and Blake had a blast going through the mazes together.”

While there were certain rides pregnant Kylie couldn’t go on, she “made sure Travis went ahead and had fun,” said the onlooker, adding that the reality star kept her belly “under wraps in a big hoodie and leggings.”

A source recently told PEOPLE that Kylie — who hasn’t publicly addressed her pregnancy but seems to be teasing the news on Snapchat and YouTube — “still wants to keep a low profile” and “prefers to stay home” at the moment.

“Even though this is a very exciting time for her, she wants to be more private for now and is doing her best to stay out of the public eye,” the source said.

“She feels good, but her body is changing,” the source explained. “She doesn’t want to be photographed. At the moment, she wants more privacy. She has family and friends come to her house instead so she has company. She’s very excited about the baby though. She talks about the baby nonstop. She’s already shopping like crazy.”

Kylie JennerCredit: Kylie Jenner/Snapchat

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Kylie was noticeably absent from photos of the family shooting their Keeping Up with the Kardashians Christmas special at Kris’ home with now-retired Olympic medal-winning figure skater Nancy Kerrigan. A source told PEOPLE that she was present during filming, but opted not to ice skate.

“It was a scheduled taping,” the source said. “She kept in the background, but seemed great.”

Kylie’s baby won’t be the only addition to the family. Kardashian West confirmed in a supertease for season 10 of KUTWK that she is expecting her third child with husband Kanye West via surrogate, while Khloé Kardashian is expecting her first child with NBA boyfriend Tristan Thompson.