Lyrics:

[Verse 1]
You know how to make me weak in the knees
When you pour yourself all over me
But somebody broke you back in the day
Now you never ever love
Now you only wanna play

[Chorus]
I cry when you do, I cry when you don't
Why won't you tell me what, what you want with me
One day we're together then we're apart
Why won't you let me fill up your empty heart

[Verse 2]
There's a big old hole in the middle of you
Cause somebody left you black and blue
Yeah we all make promises we can't keep
And they're paper thin but cut so deep

[Chorus]
I cry when you do, I cry when you don't
Why won't you tell me what, what you want with me
One day we're together then we're apart
Why won't you let me fill up your empty heart
Why won't you let me fill up your empty heart

[Bridge]
Fill up your empty heart
Fill up your empty heart
Fill up your empty heart
Fill up your empty heart (I just wanna fill it up baby)
Fill up your empty heart (Why won't you let me)
Fill up your empty heart (I want you to let me)
Fill up your empty heart (I just wanna)
Fill up your empty heart (Fill it up, fill it up, yeah)

[Chorus]
I cry when you do, I cry when you don't
Why won't you tell me what, what you want with me
Fill up your empty heart
Fill up your empty heart
One day we're together then we're apart
Why won't you let me fill up your empty heart
Fill up your empty heart
Fill up your empty heart
I cry when you do, I cry when you don't
Why won't you tell me what, what you want with me
Fill up your empty heart
Fill up your empty heart (I just wanna)
Why won't you let me fill up your empty heart