The father listened in on the first and heard them talking.

He went to the second door and heard laughing.

Finally he went to the third daughter's door and heard nothing at all.

Later that night he asked each one what they did. The first daughter said that she got to know him.

The second daughter said her guy was tickling her.

The father asked the third daughter why her room was so silent.

The daughter replied, "Well you told me never to talk with my mouth full."