Lenny does play really well with most of the dogs he meets, sometimes after awhile if the play gets too rough, he gets pretty intense, but respons to that's enough. It was different from the start when he met the boxer pups, both of whom were almost ayear old and much larger than he is. I wonder if he was reacting to their tall and stiff legged approach. It happened so fast, he just flew at the other boxer and did not start out with any kind of play stance, jumping up on the dog with his front feet at shoulder, and very snarly, loud towards the other dogs head. He stopped pretty fast when I reprimanded him, but I didn't let him continue playing. I will see how it goes the next time. I appreciate all the feedback. I may be a little extra on guard about it because I have read that two male boxers can get into treouble with each other over dominance issues.