it was a god lip sync, and the fact that the rest of the face kept moving between the three or four draiwngs added to the continuity of the mouth as it wiggled around. the only thing that i would change is the mouth itself. A little more detail in each mouth position would go a long way, specifically just in darkening it. (well technically lightening it because the background was black, and the lines were subtracted from it with a sort of peach color but... ) i just mean, like filling in the gap between the upper lip and the tongue, or between the upper teeth and the tongue, to kind of make it darker there, it would be more entertaining to watch if the mouth was made up of more lines and stuff!
but i liked it! very well done, ESPECIALLY considering it's the first lip sync you've done!