It happened while I did some ab crunches with baby sitting on top of me. I would lay flat on the floor and ask Where's daddy? then bringing my head as close to baby's face as possible. Ben became amused instantly, and after a couple of crunches... he just laughed.
Laughing harder still was Mommy, as I had to keep on crunching my abs to keep our son entertained. As you'll guess (correctly) I was about to die of exhaustion in only a short while, but Ben wanted more and more. So I went on until it was physically impossible to continue (No, I won't tell how many crunches).
Was it all part of a sinister plan to get Daddy some exercise? God knows he needs it.