It is a K-pop, disco-pop, synth-pop, and bubblegum song about a young girl's unrequited love and the shame she feels because of it.

"Cupid" peaked at number 17 on the Billboard Hot 100, where its 10-week-long chart run made it the longest-charting song by a K-pop girl group, and at number eight in the UK, where Fifty Fifty became the first K-pop girl group to reach the chart's top 10.

The song also reached the top 10 of the charts in South Korea and Australia while peaking at number one on the Billboard Global Excl.

[4] Before releasing "Cupid", the group debuted with the extended play (EP) The Fifty, the lead single of which was "Higher", in November 2022.

[4][8][9] The Twin version, named as such due to it being mostly the same as the original with some changes, was intended by Siahn to make the song marketable globally.

[12] The music video was released on February 23, the same day where the group was performing the single for the first time on stage at M Countdown.

[14] "Cupid" was produced by Siahn, written by Keena and Ahin, and composed by Swedish producers Adam von Mentzer, Mac Felländer-Tsai, and Louise Udin, all of whom also co-produced and co-arranged the song and were paid $9,000 for their contributions to the song.

[3] On April 8, 2023, an official sped-up rendition of "Twin" version was released on various streaming platforms under the artist name "Sped Up 8282" through Warner.

Its lyrics describe a young girl's unrequited crush and her feeling dumb for falling in love.

[6] In the song's chorus, the group sings, "I gave a second chance to Cupid/I believed you, I'm so stupid/Let me show you, my secret love, is it real?/Cupid is so dumb," with some lyrics in Korean.

[5] Molly Raycraft of The Guardian described the song as "sweet but sardonic pop reminiscent of hits by Ariana Grande and Doja Cat" with "a nostalgic sound".

[30] Rolling Stone, on its mid-year list of best songs on 2023, noted the song as a "delightful in graceful simplicity, breezing by on a disco-pop groove that has the easygoing effervescence of early-2010s pop, with vocals that exude cool confidence and winning warmth, even with its busy Doja-esque rap.

"[32] NME included it in a similar list, calling it "relatable and endearing" for portraying the emotions and the sadness for the end of a great love "without laying them on too thick".