Why does our mouth becomes watery sometime

Why does our mouth becomes watery sometime ,swhen we eat or think about the food we like?

The salivary glands present in our mouth releases saliva, which makes our mouth watery. The brain registers, that food is coming and instructs the salivary gland present underneath the tongue to produce saliva, which helps in breakdown of food as we chew it. Thus, making it softer as it enters the gut.