A lady and her dog were enjoying a stroll in the park when her dog was mounted from behind by a large Rottweiler. The Rot was really humping away and the lady was frantically trying to break them up, to no avail.
A small boy walked up and stuck his finger in the Rots "backside", and the action immediately stopped.
The lady was amazed. "How did you do that?" she asked.
The little boy said, "That's my dog! He can dish it out, but he can't take it!"