I can't be the only one who feels sorry for the ignorant ladies...
Getting peed on is nothing to joke about IMO, just gross. When I used to get questions like these (rarely happens anymore, since one of my new yorkies is very hostle to strangers and I have a terrible time trying to train him to be "nice"), I always would explain with minimal sarcasm that yes, they are full grown, no, they were not the same breed as Toto, yes, they act much the same as any other dog and love to play fetch and do anything any other terrier likes to do (including roll in skunk spray if you let them).
Igorant people just need to be educated if they will listen, at least the ladies agreed Rocco was cute, and that is a start.