Three mothers
One day a brunette mother walks in her daughters room, she sees a cigarette pack on the floor and says, I didnt know my daughter smoked.
The same day a redheaded mother is looking in her sons room and sees a beer bottle on the floor and says, I didnt know my son drank.
The same day, a blonde mother is in her daughters room and sees a condom on the floor and says, I didnt know my daughter had a penis!