I'm not sure if they're right, but these are the chords I use. For the Em and G 
chords, hold down the B and e strings on the third fret. Enjoy!

Dsus4
Girl, that should be me driving to your house
                 Asus4Knocking (x02230@1)on your door, kissing you on the mouth
                EmHolding (022000@1)on your hand, dancing in the dark
                 G'Cause (320003@1)I was the only one who loved you from the start

Dsus4 (xx0233@1)                        G (320003@1)            Asus4But (x02230@1)now when I see you with him it tears my world apart

Dsus4
Because I've been waiting
                 Asus4All (x02230@1)this time to finally say it
                   EmBut (022000@1)now I see your heart's been taken
                     GAnd (320003@1)nothing could be worse
GBaby, (320003@1)I loved you first
Dsus4 (xx0233@1)                               Asus4Had (x02230@1)my chances, could have been where he is standing
                      EmThat's (022000@1)what hurts the most, girl, I came so close
                     GBut (320003@1)now you'll never know

Baby, I loved you first

Dsus4
Girl, that should be me calling on your phone
                  Asus4Saying (x02230@1)you're the one and that I'll never let you go
             EmI (022000@1)never understood what love was really like
                      GBut (320003@1)I felt it for the first time looking in your eyes

Dsus4 (xx0233@1)                        G (320003@1)               Asus4But (x02230@1)now when I see you with him my whole world falls apart

Dsus4
Because I've been waiting
                 Asus4All (x02230@1)this time to finally say it
                   EmBut (022000@1)now I see your heart's been taken
                     GAnd (320003@1)nothing could be worse
GBaby, (320003@1)I loved you first
Dsus4 (xx0233@1)                               Asus4Had (x02230@1)my chances, could have been where he is standing
                      EmThat's (022000@1)what hurts the most, girl, I came so close
                     GBut (320003@1)now you'll never know

Baby, I loved you first

EmFirst (022000@1)touch, first kiss
Dsus4
First girl who made me feel like this
EmHeartbreak, (022000@1)it's killing me
Asus4
I loved you first ‒ why can't you see?

Dsus4
Because I've been waiting
                 Asus4All (x02230@1)this time to finally say it
                   EmBut (022000@1)now I see your heart's been taken
                     GAnd (320003@1)nothing could be worse
GBaby, (320003@1)I loved you first
Dsus4 (xx0233@1)                               Asus4Had (x02230@1)my chances, could have been where he is standing
                      EmThat's (022000@1)what hurts the most, girl, I came so close
                     GBut (320003@1)now you'll never know
G (320003@1)                 Dsus4Baby, (xx0233@1)I loved you first
                    Asus4Baby, (x02230@1)I loved you first
                    EmBaby, (022000@1)I loved you first
    GOh, (320003@1)yeah

Baby, I loved you first