Joke: Thunderstorm

One summer evening, during a violent thunderstorm, a mother was
tucking her small boy into bed. She was about to turn off the light
when he asked with a tremor in his voice, "Mommy, will you sleep
with me tonight?"

The mother smiled and gave him a reassuring hug.
"I can't dear," she said.
"I have to sleep in Daddy's room."

A long silence was broken at last by a shaken little voice saying,
"The big sissy."