Why do guys try to impress girls?!?

i was walkin w a buncha frens n these 3 boys lika yr older than us(i knew only onof them) kept on followin us n then they were in front of us n they were acting all loud n hyper n they kept on lookin bak at us 2c if we were impressed or wtvr n we were all like wth?! i dnt get it y do they do that?