The children began to say:
'Red............cherry,'
'Yellow.........lemon,'
'Green..........lime,'
'Orange........orange.'
Finally the professor gave them all honey Polos. After eating them for a few moments none of the children could identify the taste.
'Well,' he said 'I'll give you all a clue. It's what your mother may sometimes call your father.'
One little girl looked up in horror, spat hers out and yelled:
Spoiler: