Leave it up to Billie Eilish [1] to go against the status quo with her signature sense of style [2]. On Aug. 15, the 21-year-old continued her obsession with the Y2K aesthetic [3] while performing at the Sziget Festival in Budapest, Hungary. In true Billie Eilish fashion, she took the stage in a black oversize jersey that read "FAMOUS" along with the number 99 and chose the most unconventional bottom — a pair of red mini dolphin shorts layered over see-through black biker shorts and sheer tights. She slipped on red, black, and white striped socks with a classic pair of Air Jordan 3s — originally released in 1988 — further accessorizing with a red skull-printed beanie, long fingerless gloves with black and white stars, and a variety of silver jewelry.

Eilish's latest look stays true to her well-known reputation for unusual outfit combinations, specifically embracing trends from the '90s and early 2000s. She's fearlessly rocked short shorts multiple times, from the tiny camouflage booty shorts [4] she wore over fishnet tights for an Instagram photo shoot to the sheer biker shorts [5] she sported in a similar photo dump. The young star has experimented with other Y2K trends, including a pleated schoolgirl skirt over baggy pants [6], oversize graphic tees and Moon Boots [7] at the gym, and pinstripe oversize shirts, which she confidently sported at the "Barbie" premiere [8] last month.

The "Happier Than Ever" singer has also explored other style eras and aesthetics. Recently, she channeled the '50s in a yellow A-line shirtdress for the "What Was I Made For?" music video [9] and her inner "soft girl" with a blue floral ruched dress by Yuhan Wang for Easter [10]. Eilish has even hopped on the naked-dress trend [11] with a sheer black minidress for her Eilish No. 2 fragrance campaign [12] and a Simone Rocha lace gown at the 2023 Met Gala [13].

Get a few more angles of Eilish's boundary-pushing concert outfit ahead.

Billie Eilish Performing at the 2023 Sziget Festival in Budapest, Hungary