Complete the mini-game where Rufus Brushes his teeth, without skipping.
The minigame isn't difficult, just mimic the motions Cletus does with his toothbrush as close as possible.
There isn't really a cheat sheet to use with this so just try your best.
When Cletus moves his brush side to side, try to keep up with his pace. Same when he moves it in circles and when he lowers his brush, do that as well.