Duke listen really well to me when we are in the house or in our yard. He is even good when we are out on our own, but the minute another dog comes around he becomes stupid. All he wants to do is play with the dog, and he wont even pay attention to me. I've tried having him on his leash and getting him to sit, and give him treats. But he just wants to pull me and play. Is there something I can do to stop this?