[Wendy] Hey! Oh~no~ooh~
(Seulgi – Alright, alright)
(Irene – Aaah!)
[Joy] Bad boy (Seulgi – Yeah)
Bad boy (Seulgi – Oh~ooh)
Alright 1 2 5 uh

[Verse1] – [Irene] Yojeum na jogeum paenik sanghwang ha
Soljjiki wanjeon holliginde hey
[Seulgi] Meorissok eotteon nyeoseok geu
Saenggak hanappuniya one one one one
One one one one one one one one

(Red Velvet – Ah~ah~ah)(Irene – Alright, hey)

[Bridge1] – [Joy] Chingudeul Say gyaeneun andwae
Neomu nappa nega dacheo
(Red Velvet – Ah~ah~ah)
(Joy – Uhm)
[Yeri] Nuga mallyeo naega joeumyeon
(Seulgi – Yeah yeah yeah)
Ganeun geojo (Seulgi – Oh, oh my god)

[Chorus] – [Wendy] Ey oh my god!
He’s a Really Bad Boy
He’s a Really Bad Boy
[Red Velvet/(Joy)] (Ey oh my god) he’s a Really Bad Boy
He’s a really really really really Really Bad Boy
(Wendy – Ey yeah yeah yeah)

[Hook] – [Red Velvet] You’re so bad boy (Seulgi – Oh oh oh oh~)
You’re so bad boy (Seulgi – Oh oh oh oh~)
You’re so bad bad bad bad
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)
Bad bad bad bad boy
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)

[Verse2] – [Irene & Yeri]
Bang bang pow, he’s a Really Bad Boy
Jalsaenggin geu eolgul hana mitgo sandaeyo
[Joy] Gwaenchantamyeon neol naega gildeuryeo
Bolkke boy mine mine mine mine

(Red Velvet – Ah~ah~ah)(Yeri – Alright, hey)

[Bridge2] – [Irene] Meottaero hae heorakalkke
Inneun himkkeot nappajeo bwa
(Red Velvet – Ah~ah~ah)(Wendy – Uhm)
(Seulgi – No)
[Yeri] Geureon niga byeonhaegal ttae
Jaritaji (Wendy – Oh, oh my god)

[Chorus] – [Seulgi] Ey oh my god! (Joy – Oh my god, oh my god)
He’s a Really Bad Boy
He’s a Really Bad Boy (Joy – Oh my god)
[Red Velvet/(Wendy)] (Ey oh my god) he’s a Really Bad Boy
He’s a really really really really Really Bad Boy
(Wendy – Ah~ah~ah)

[Hook] – [Red Velvet] You’re so bad boy (Seulgi – Oh oh oh oh~)
You’re so bad boy (Seulgi – Oh oh oh oh~)
You’re so bad bad bad bad
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)
Bad bad bad bad boy
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)

[Bridge3] – [Joy] Akkaweo dareun i nan mot jweo
Bwa naega neol saranghaneunde
[Seulgi] Nugurado heumppeok ppajeobeoril
(Irene – Aaah!)
[Yeri] You’re a bad boy and you’re bad for me
You’re a bad boy and you’re bad for me
(Wendy – Amuri nappado nan joa)
You’re a bad boy and you’re bad for me
You’re a bad boy and you’re bad for me
(Wendy – Bwa sesange neon bichi na)
You’re a bad boy and you’re bad for me
You’re a bad boy and you’re bad for me
(Wendy – Nugurado heumppeok ppajeobeorilgeol)
[Irene] You’re a bad boy and you’re bad for me
You’re a bad boy and you’re bad for me
You’re a bad boy and you’re bad for me
(Irene/Seulgi – You’re a bad boy and you’re bad for me)

[Beat] [Irene Lead/Red Velvet]
Oh my god he’s a Really Bad Boy
He’s a really really really really Really Bad Boy

[Hook] – [Red Velvet] Oh my god (Seulgi – Oh oh oh oh~)
He’s a Really Bad Boy (Seulgi – Oh oh oh oh~)
He’s a Really Bad Boy
Oh my god
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)
He’s a Really Bad Boy
He’s a Really Bad Boy
(Seulgi – Ey yeah yeah yeah yeah yeah yeah)

[Outro] – [Wendy] Oh my god (Irene – Aaah!)
[Joy] He’s a Really Bad Boy
He’s a Really Bad Boy
He’s a Really Bad Boy
(Seulgi – He’s a Really Bad Boy!)
[Red Velvet] Oh my god he’s a Really Bad Boy
(Wendy – He’s a Really Bad Boy!)
He’s a really really really really Really Bad Boy
(Wendy – Wooh~ooh~)