That smile of J.J. Watt's is pretty bright -- but his future as a dancer sure isn't!
The NFL defensive end was at the Houston YMCA hanging out with a group of children there for a summer camp, when the kids decided they were going to teach Watt how to do the Nae Nae!
[ Related: Riley Curry Does A WAY Better Nae Nae Than Watt! ]
The results were HIGHlarious -- Watt actually fell to the ground! It wasn't because of the dance, though -- more like because the kids were so adorbz!