I have a question for all the corgi owners out there. Boris is about 41/2 months old, we took him to a 6 week puppy training and try to work with him for about 5 min a day on everything. We were told that the nipping and mouthing was a phase due to his teething and he has improved his day one but he still lunges at your face playfully or mouths your fingers or arm. What should i do to totally stop this behavior even when playing. We have tried the water bottle as well.