Obviously this is an acoustic rendition and isn't the way Justin plays it, but 
sometimes you just can't be bothered to retune. This is for those occasions.

I play with the Capo on the 4th fret with standard tuning. Obviously change the 
capo position depending on your voice if needed.
Strum pattern is very simple. If you're a beginner and are having some problems 
then I'd recommend persevering and listening to the song over and over 
(fortunately it's a great song!). 
If you become dependent on strum patterns then you won't develop your ear or rhythmic abilities.

Any questions, appraisals or death threats then write to Josh_Turner6@msn.com

By the way, check out Anna Scouten's cover. 'tis incredible! 
http://www.youtube.com/watch?v=FuwfDZlJ0bI

Hope it's correct and you all enjoy my first ever tab!

These are the chord positions used:
Em7      - (022033)
Dsus4    - (xx0233)
Cadd9    - (x32033)
G        - (320033)
Dsus4/F# - (2x0233)

Remember - Capo on the 4th!

       Em7                        Dsus4
Well I met you at the blood bank
        Cadd9
We were looking at the bags
             Em7                Dsus4
Wondering if any of the colours
                   Cadd9              
Matched any of the names we knew on the tags
               G
You said: "see look that's yours"
           Dsus4/F#     
Stacked on top with your brothers
             Em7                
See how they resemble one another?
              Cadd9              
Even in their plastic little covers
           Cadd9           Em7    Dsus4
And I said I...... know it well........

      G      
That secret that you know
               Dsus4/F#               
That you don't know how to tell
   G  
It f**ks with your honour
       Dsus4/F#
And it teases your head
        Em7         
But you know that it's good girl
           Cadd9         
'cause its running you with red.

         Em7                   Dsus4
Then the snow started falling
        Cadd9
We were stuck out in your car
         Em7                    Dsus4
You were rubbing both my hands
        Cadd9
Chewing on a candy bar
                      G
You said: "ain't this just like the present"
      Dsus4/F#
To be showing up like this
          Em7
There's a moon waning crescent
   Cadd9
We started to kiss
           Cadd9           Em7    Dsus4
And I said I...... know it well........

     G
That secret that we know
              Dsus4/F#
That we don't know how to tell
        G
I'm in love with your honour
       Dsus4/F#
I'm in love with your cheeks
            Em7
What's that noise up the stairs babe?
        Cadd9
Is that Christmas morning?
           

    Cadd9           Em7    Dsus4
And I...... know it well........ (Repeat and fade 'til heart's content)