It may have to do with "territory". Where did they meet originally? At the other house? at the park? neutral territory? If this was the Yorkies first time coming to your house - then they invaded your boyz' territory and that may be a different story - protecting my territory - whereas on "the Yorkies" territory or in neutral territory, it wasn't an issue.
Just a thought.........
__________________  Rex & Rowdy's Mom  |