Sometimes, videos that go viral don't have to be extremely funny or outrageous. Sometimes they can just be about regular things that happen all the time, but just happen to be recorded at the right time and place.
Case and point is this child's reaction to becoming a big brother. He's too cute! And polite! And probably the most mature response for a five year old. These parents should be proud and he seems like he's gonna make a great big bro.
Unless that baby sleeps in his bed. No excuses for that.