Hailey Bieber goes wild at Kylie Jenner's kitty-themed birthday party: See pics

Hailey Bieber got a little too quirky at Kylie Jenner's all-pink, kitty-cat-themed 29th birthday party over the weekend.

In behind-the-scenes photos from the celebration, one moment shows Bieber licking the side of a friend's waist while wearing a pink feather boa and a plastic crown.

She also posted a photo of herself mixing up a special cocktail for the party, jokingly naming it after herself.

Jenner hosted the birthday bash at her home in Los Angeles on Friday, with guests including her sisters and close friends.

She shared photos on Instagram showing herself in a hot pink latex dress, paired with a feather boa, feathered heels, and a matching headband.

The dessert table was packed with donuts, snacks, and three birthday cakes. One cake was shaped like Jenner's body, another featured gemstone, and the third had a cat theme with the words "Kitty Kylie."

A group photo showed Jenner posing with her guests, including Bieber and her sisters, all dressed in pink with tiaras and boas. In one moment, Kendall Jenner was seen kissing her sister on the cheek.

Kim Kardashian also shared a birthday tribute featuring flowers and a cat-themed cardboard cutout, while Khloé Kardashian showed off a room filled with colourful balloons.

Jenner's daughter, Stormi, also made an appearance at the party. Khloé's ex, Tristan Thompson, was seen attending and later leaving in his car.

Jenner's actual birthday falls on Monday, and she's expected to celebrate again then.