One of my favourite songs! so funny.. 

{VERSES} - G C Em D

G                       C                     Em                           D
It's friday night, me and marty, got some girls over, we're gonna party.. etc

{PRE-CHORUS} - G C Em D (palm muting)

         G                                             C                       Em                  D
Say I, woke up in the morning with a pain in my ass, don't ask baby cause I don't understand etc..

{CHORUS} - G C Em D continued strumming

{BRIDGE} - Am C G D

Am                                C                         G                                       D
What am i going to do, I am so confused, recently i've been thinking one direction are pretty cool etc.

Link to the song;

http://www.youtube.com/watch?v=pYRNjYdzWr8