When Sam says to Austin at the game what are tu doing he says something I should have done along time ago. What does he mean por this line. Did he know her from kindergarden and she had a thing for him. Im confused.

He means that he should have done it when he first found out the she was Princeton Girl.

It means that he should have done it before. He didnt know he loved her but he now knows that he wishes he was different & have loved her from the start!!

he means he shouldve have did it when he found out she was PrincetonGirl

i think he meant he should have kissed sam when he found out sam was princeton girl because they kissed after that line so yeah

he is say that he should have kissed her alone time ago.

He meant that when he found out that she is the Princeton Girl,he should have believed her as the person he chatteted and shared all his thoughts. He meant to tell her what he really felt like from the moment he fell for her.