[Intro: Camila Cabello & Shawn Mendes]
Ah-ah, he-hey
Ah-ah, ah-ah
Ah-ah, he-hey
Ah-ah, ah-ah

[Verse 1: Camila Cabello]
He knows
Dirty secrets that I keep
Does he know it's killin' me?
He knows, he knows
D-D-Does he know
Another's hands have touched my skin?
I won't tell him where I've been
He knows, he knows, he knows

[Pre-Chorus: Shawn Mendes, Camila Cabello & Shawn Mendes & Camila Cabello]
It's tearing me apart
She's slipping away (I'm slippin' away)
Am I just hanging on to all the words she used to say?
The pictures on her phone (The pictures on my phone)
She's not coming home (I'm not comin' home)
Comin' home, comin' home

[Chorus: Shawn Mendes, Shawn Mendes & Camila Cabello]
I know what you did last summer (Ah-ah)
Just lied to me, "There's no other" (He-hey)
I know what you did last summer
Tell me where you've been
I know what you did last summer (Ah-ah)
Look me in the eyes, my lover (He-hey)
I know what you did last summer
Tell me where you've been
[Post-Chorus: Camila Cabello, Shawn Mendes & Camila Cabello & Shawn Mendes]
I know, I know, I know, I know (Ah-ah), I know, I know, I know (He-ey)
I know, I know, I know, I know (Ah-ah), I know, I know, I know (Ah-ah)
I didn't mean it, no (Ah-ah), I didn't mean it, mean it, no (He-hey)
Can't seem to let you go (Ah-ah), can't seem to hold you close (Ah-ah)

[Verse 2: Shawn Mendes]
I know
When she looks me in the eyes
They don't seem as bright no more, no more
I know
That she loved me at one time
Would I promise her that night
Cross my heart and hope to die

[Pre-Chorus: Shawn Mendes, Camila Cabello & Shawn Mendes & Camila Cabello]
It's tearing me apart (It's tearin' me apart)
She's slipping away (I'm slipping away)
Am I just hanging on to all the words she used to say?
The pictures on her phone (The pictures on my phone)
She's not coming home (I'm not comin' home)
Oh, nah, nah, nah, oh-yeah

[Chorus: Shawn Mendes, Shawn Mendes & Camila Cabello]
I know what you did last summer (Ah-ah)
Just lied to me, "There's no other" (He-hey)
I know what you did last summer
Tell me where you've been
I know what you did last summer (Ah-ah)
Look me in the eyes, my lover (He-hey)
I know what you did last summer
Tell me where you've been
[Bridge: Shawn Mendes, Camila Cabello & Shawn Mendes & Camila Cabello]
I know, I know, I know, I know, I know, I know, I know
I know, I know, I know, I know, I know, I know, I know (No, no)
Can't seem to let you go
Can't seem to keep you close (Hold me close)
I can't seem to let you go
Can't seem to keep you close (You know I didn't mean it, though)
Tell me where you've been lately
Tell me where you've been lately (Just hold me close)
Tell me where you've been lately
Tell me where you've been lately (Do-Don't-Don't let me go)
Can't seem to keep you close
I can't seem to let you go (I didn't mean it, though)
I know you didn't mean it, though
I know you didn't mean it, though (I don't wanna let you go)
Tell me you didn't mean it, though (No, no, no)
Tell me you didn't mean it, though (Can't seem to let you go)
I know you didn't mean it, though (Seem to let you go)
I wanna know you mean it, though (Hold me close)
I know you didn't mean it, though (Just hold me close)
I know you didn't mean it, though
I can't seem to let you go, can't seem to hold you close

[Chorus: Shawn Mendes & Camila Cabello]
I know what you did last summer (Ah-ah)
Just lied to me, "There's no other" (He-hey)
I know what you did last summer
Tell me where you've been
I know what you did last summer (Ah-ah)
Look me in the eyes, my lover (He-hey)
I know what you did last summer
Tell me where you've been
[Post-Chorus: Shawn Mendes & Camila Cabello, Camila Cabello]
I know, I know, I know, I know (Ah-ah), I know, I know, I know (He-hey)
I know, I know, I know, I know (Ah-ah), I know, I know, I know (Ah, yeah)
I know, I know, I know, I know (Ah-ah), I know, I know, I know (He-hey)
I know, I know, I know, I know (Ah-ah), I know, I know, I know (Ah-ah)
I know