Dad likes to tease puppies, because he likes puppies very much, and he likes to be close to puppies. Besides, Doby's puppy can make him happy physically and mentally, which is also a way to relieve stress and relax himself.

Most of the reasons why humans tease puppies are because dogs are very similar in personality to humans, and dogs are very loyal, willing to be close to people and able to build trust with each other.