At the end, Thomas spills all the eggnog on his hand and the carpet. When he realizes it, first he shows a face of "whoops" then he breaks out of character and starts laughing while trying to continue the dance.
Next to this title, this caption appears: "This is what I get for NOT LOOKING AT WHAT I'M DOING" which is a reference to how he spills the eggnog on his hand and over the carpet at the end of the video, which was something not planned or scripted.