After enjoying a nice refreshing drink of water, a happy horse named Root repeatedly and audibly smacked his lips and wagged his tongue while being bathed. According to his human T Stephens, “…he likes the way it feels.”
In 2013, Andi Solowka posted a video of a horse named Burke loudly flapping his lips in anticipation of an incoming meal.
This is one of our horses smacking his lips because he is anxious to get his grain. This never fails to make me laugh.