Super easy song! I love Alexz!  

Verse 1
G                        Am
He broke in my heart and took my gold 
G                            Am
And after all that I've been told
C                     Am
Horror stories that I read 
C                           Am
While mom was putting me to bed

G                     Am
I put a lock on every door
G                          Am
He wants to get inside I'm sure 
C                       Am
He's only there to mess around 
C                     Am
Be the talking of the town 

Chorus
D        Am                     G
A thief, burning my whole world down 
D        Am                     G
A thief, turning my whole world around 

Verse 2

G                        Am
I know I've failed every test 
G                             Am
He knew which button he could press
C                           Am
My heart it beats out of my chest 
C                      Am
It's never getting any rest 

G                         Am
Didn't want him to see me cry
G                       Am
But every word became a lie
C                   Am
Only he can read my mind
C                         Am
His every touch is like a crime 

Chorus
D        Am              G
A thief, burning my home down 
D        Am                     G
A thief, turning my whole world around 

End Bridge

Am                       Em
Tell me what am I to do (better watch her)
Am                       Em
Tell me who to talk too (talk to a doctor)
Am                       Em
I really quit loving you (it won't matter) 
E                             F           Ab(slide down 2 frets from F chord)
So why am I talking you in to letting you still break in

Chorus
D        Am              G
A thief, burning my home down 
D        Am                     G
A thief, turning my whole world around 

That's basically it!