Check out this footage of Paul McCartney having a BLAST at the NY Rangers game this weekend -- yelling, screaming, towel-whirling -- while the guy next to him looks COMPLETELY MISERABLE.
By the way, that guy is Paul's son, James.
It's funny stuff ... the crowd went crazy for the Beatles legend -- despite the fact the Rangers got beat down by the Washington Capitals in a 7-3 rout.
Paul was a man about town this weekend -- he appeared on 'SNL' on Saturday and hit up a Brooklyn Nets game on Sunday.
Pretty rad, right?