A family of 3 ( father

A family of 3 ( father, mother, son) went on their monthly family outings to the zoo. Well little Billy seen 2 monkeys mating and asked his father what they were doing, Shocked by this question the father said baking a cake. Then little billy seen 2 bears mating and asked his monther what they were doing, shocked by this question the mother said baking a cake.When Billy came home from school, he told his parents, i know what you guys were doing while i was at school! His parents said what. He said you were baking a cake! They aksed him how did he know, he said cause i licked the icing off of the sofa!