hi, we have a new bearded collie puppy 2mths and our 15mth border collie (dutch) will not play with him, dutch is not aggressive or mean he just acts as if the puppy is invisible. When dutch does see other dogs in the park he is so over friendly we have to call and call to get him back. Will this friendship blossom between the pup and dog? can someone help with some tips to help the friendship start. thanks