My 4 month old male papillon loves everyone and covers them with kisses. Except my dad. My dad loves animals and it bothers him that the puppy hates him. He tried giving him treats and toys but it hasn’t helped. It started with just barking and growling while hiding behind me, but now he tried to bite him. I have been strict and tell him no over and over when he barks and growls but it has not worked. Help please!!! how should I handle this and train my puppy so he is not aggressive?