[Intro: Wendy, Seulgi, Joy]
Hey! No (Alright, alright)
Bad boy, bad boy (Yeah, yeah, oh-ooh!)
Alright, 1, 2, 5, uh!

[Verse 1: Irene, Seulgi]
Kickin' it with my girls, let's party (Ha!)
Sipping on milk and chocolate sundaes (Hey!)
Having such a good ass time, now all I need is that one guy
One, one, one, one
One-one-one-one-one-one-one-one

[Pre-Chorus: Yeri, Joy, Irene, Seulgi]
Ah, ah, ah (Alright, hey!)
All the girls say, all the girls say
All the girls say, all the girls say
Ah, ah, ah (Ooh, yeah, yeah, yeah)
All the girls say, all the girls say
All the girls say, all the girls say (Oh, oh my God!)

[Chorus: Wendy, Joy, Wendy & Joy, Yeri & Joy]
(Hey, oh my God!)
Oh my god! He's a really bad boy
He's a really bad boy
He's a really bad boy
Hey, oh my God! (Oh my god)
He's a really bad boy
He's a really, really, really, really
Really bad boy (Hey, yeah, yeah, yeah!)
[Post-Chorus: All, Seulgi]
You're so bad, boy (Ah, ah, ah)
You're so bad, boy (Ah, ah, ah)
You're so bad, bad, bad, bad (Hey yeah, yeah!)
Bad, bad, bad, bad boy (Hey yeah, yeah!)

[Verse 2: Irene & Yeri, Joy]
Bang, bang, pow, he's a really bad boy
How he plays with hearts instead of playing with his toys
And I don't really care 'cause I'm really in love (Boy)
Mine, mine, mine, mine

[Pre-Chorus: Yeri, Irene, Seulgi, Wendy]
Ah, ah, ah (Alright, hey!)
All the girls say, all the girls say
All the girls say, all the girls say
Ah, ah, ah (No!)
All the girls say, all the girls say
All the girls say, all the girls say (Oh, oh my God!)

[Chorus: Seulgi, Joy, Seulgi & Joy, *Wendy*, Irene & Joy]
(Hey, oh my God!)
Oh my god! He's a really bad boy (Oh my God, oh my God)
He's a really bad boy
He's a really bad boy (Oh my God)
*Hey, oh my God!* (Oh my god)
He's a really bad boy
He's a really, really, really, really
Really bad boy (Oh)
[Post-Chorus: All, Seulgi]
You're so bad, boy (Ah, ah, ah)
You're so bad, boy (Ah, ah, ah)
You're so bad, bad, bad, bad (Hey yeah, yeah!)
Bad, bad, bad, bad boy (Hey yeah, yeah!)

[Bridge: Joy, Seulgi, Yeri, Wendy, *Irene*]
I know that I need someone to, uh
Look after me and all I do
But no one else makes me smile the way you do
You're a bad boy and you're bad for me
You're a bad boy and you're bad for me
And I know that I need someone to
(You're a bad boy and you're bad for me)
(You're a bad boy and you're bad for me)
Look after me and all I do
(You're a bad boy and you're bad for me)
(You're a bad boy and you're bad for me)
But no one else makes me smile the way you do
(*You're a bad boy and you're bad for me*)
(*You're a bad boy and you're bad for me*)
Whoa, whoa
(*You're a bad boy and you're bad for me*)
*You’re a bad boy and you’re bad for me!*

[Chorus: Irene]
Oh my God, he's a really bad boy
He's a really, really, really, really
Really bad boy
[Post-Chorus: Joy & All, Seulgi, Joy]
Oh my God, he's a really bad boy (Ah, ah, ah)
He's a really bad boy (Ah, ah, ah)
He's a really bad boy, uh
Oh my God, he's a really bad boy (Hey yeah, yeah!)
He's a really bad boy (Hey yeah, yeah!)
He's a really bad boy, uh

[Chorus: Wendy & Joy, Joy, Joy & All, Wendy]
Oh my God! He's a really bad boy
He's a really bad boy
He's a really bad boy (He's a really bad boy)
Oh my God, he's a really bad boy (He's a really bad boy!)
He's a really, really, really, really
Really bad boy (Whoa!)

[Outro: Irene]
Mmm