The G doesn't have to be played as Chord, the bass note is enough, the C is played 
with a G on the high e.

Intro: C G Am G 

C
Hey, boy you never had much game
                 G  Am
Thought I needed to upgrade
                                G
So I went and walked away way way
C
Now, I see you've been hanging out
                 G      Am
With that other girl in town
                                      G
Looking like a pair of clowns clowns clowns

BRIDGE:
C
Remember all the things that you and I did first?
                               G
And now you're doing them with her
Am
Remember all the things that you and I did first?
                              G
You got me, got me like this
C
And now you're taking her to every restaurant
                        G
And everywhere we went, come on!
Am
And now you're taking her to every restaurant
                              G
You got me, got me like this

CHORUS:
C
Boy you can say anything you want 
                                    G
I don't give a shh, no one else can have ya
Am
I want you back I want you back
                            G
Wa-want you, want you back
C
I broke it off thinking you'd be cryin'
                                    G
Now I feel like shh looking at you flyin'
Am                              
I want you back I want you back
                            G
Wa-want you, want you back

C 
Please, this ain't even jealousy
                  G      Am
She ain't got a thing on me
                                           G
Tryin' to rock them ugly jeans jeans jeans
C
You clearly didn't think this through
                   G       Am
If what I've been told is true 
                                         G
You'll be crawling back like boo hoo hoo

BRIDGE:
C
Remember all the things that you and I did first?
                               G
And now you're doing them with her
Am
Remember all the things that you and I did first?
                              G
You got me, got me like this
C
And now you're taking her to every restaurant
                        G
And everywhere we went, come on!
Am
And now you're taking her to every restaurant
                              G
You got me, got me like this

CHORUS:
C
Boy you can say anything you want 
                                    G
I don't give a shh, no one else can have ya
Am
I want you back I want you back
                            G
Wa-want you, want you back
C
I broke it off thinking you'd be cryin'
                                    G
Now I feel like shh looking at you flyin'
Am                              
I want you back I want you back
                            G
Wa-want you, want you back

C                      G       Am
Ohhh, I thought you'd still be mine 
                                      G
When I kissed you goodbye uh oh uh oh
C                   G        Am
Ohhh, and you might be with her 
                                      G
But I still had you first uh oh uh oh

BRIDGE:
C
Remember all the things that you and I did first?
                               G
And now you're doing them with her
Am
Remember all the things that you and I did first?
                              G
You got me, got me like this

CHORUS:
C
Boy you can say anything you want 
                                    G
I don't give a shh, no one else can have ya
Am
I want you back I want you back
                            G
Wa-want you, want you back
C
I broke it off thinking you'd be cryin'
                                    G
Now I feel like shh looking at you flyin'
Am                              
I want you back I want you back
                            G
Wa-want you, want you back 

C     G  Am
Ohhh, I want you back
I want you back            G

Wa-want you, want you back

C     G  Am
Ohhh, I want you back
I want you back  
                          G
Wa-want you, want you back