Welcome to YT!! How exciting to have a puppy in the house. If at all possible have the initial meeting not be at home, where Willie may feel the need to be protective. After the initial nose sniff, hold Willie still so that Pops can sniff his bum. Monitor their contact so that Pops doesn't bully Willie, as puppies can be terrible bullies wanting the other dog to play with them all the time. You might be surprised and see that Willie actually enjoys having a puppy to play with. Boo was 5 when Gracie Ruth joined our family and it was really heartwarming to see him play with her. We just really had to watch when G started getting too rough with him, we didn't want him to ever get to the point that he felt he had to defend himself.
Good Luck, and please post pictures of the 2 of them.
