Apparently, Luke did not learn his lesson the first time.

He had his little girlfriends over this afternoon and when I checked on them, they were throwing rocks into the pool--the same pool that the pool guys had come and cleaned TODAY.

 After roaring "STOP!" I ordered Luke into the pool to fish out the rocks, which caused the girlfriends to remember some "project" they had to get home right away to do.

So, now poor Luke has been abandoned to the unenviable task of retrieving the rocks from the pool in 68 degree weather.  I should also mention that the water level was low earlier, so the hose has been filling it for the last three hours.  And we all know how warm hose water is . . . 

Thus, the facial expression.