OK OK OK

A trip into the city today.  This was in an alley. I was pointing the camera at it and saw a couple walking towards me, so I motioned for them to pass. The man stopped and looked at the wall quizzically. 
"What are you taking picture of?" (a question I often get) 
I replied, "OK OK OK!"  
"Oh!" he said. "Okay!"
I laughed. He walked past G, who said, "You walked into that one!"
"Sure did!"
And we all had a laugh.