The man smashing the guitar is Perry Miller, he is currently pretty stressed from the party, which his friends started, and when his band, The Skunks, was just preforming, they replaced him, the lead singer, with someone younger. So in an attempt to look cool, he started to smash his daughters guitar that he had with him, which he was supposed to give to her for her schools talent show, but forgot. He didint want the party to happen, and is worried about the consequences of it. Silly old goober