First Reason: Licking is a natural social behavior in dogs they show their love to owner.
Second Reason: your Puppies might lick your face as a way to seek attention from you.
Third Reason: Dogs explore the world through their senses and licking is one way they gather information.
Fourth Reason: Licking can be a gesture By licking your mouth dogs might be acknowledging your role in life.
Fifth Reason: Sometimes Dogs find comfort in the familiar scent and taste of their human companions.