Baron vs the Plumber

Hi All,
This is just a quick note, because Baron's trainer arrives soon (thank heavens). We have been working on his "greeting" behavior at the door. We have worked really hard on this, but I think there's more to be done.
Here is what happened: The plumber came this morning. I was really happy to see him, but not as happy as Baron. Although the plumber has never been to our house before, Baron greeted him warmly. He jumped on him repeatedly, despite my best efforts. The plumber is smaller than Baron and did not want to play, so Baron gave up and mugged him. This did not get either my day or the plumber's off to a good start.
All for now,
Botswain