Funny Dirty Joke

One day, a mother and her daughter were walking through the park and came across two teens having sex. The daughter asks the mom, "Mommy, what are they doing?" After thinking for a moment, the mom replies "They are making cakes, sweetie."
The next day, the mother and her daughter are walking through the zoo and they see two monkeys having sex, and the daughter asks again, "Mommy, what are they doing?" and the mother replies again, "They are making cakes, sweetie."
A few days later, the daughter walks into the kitchen and asks her mom, "Mommy? Were you and daddy making cakes in the living room last night?" and the mother replies hesitantly, "erm... yes hunny, we were." The daughter says, "Oh, okay, because i licked the icing off the couch!"