Mummy!!
Little Johnny sees his father's car passing the playground and go into the woods. Curious, he follows the car and sees his father and his aunt Jane "hugging" in the parked vehicle.
Johnny finds this very exciting and can barely contain himself so he runs home and starts to tell his mother, "I was at the playground and I saw daddy's car go into the woods with aunt Jane. I went to look for them and I saw daddy giving aunt Jane a big kiss, then he helped her take off her shirt, then aunt Jane helped daddy take his trousers off, then aunt Jane lay down on the seat, then daddy..."
At this point, Johnny's mother cut him off and said, "Johnny, this is such an interesting story. Suppose you save the rest of it for suppertime. I want to see the look on daddy's face when you tell it tonight."
At the dinner table, Johnny's mother asks him to tell his story, so Johnny starts to talk, describing the car into the woods, the undressing, laying down on the seat, and...
"...then daddy and aunt Jane did that same thing mummy and uncle Richard used to do when daddy was in the army."