Little Suzie Goes Swimming in a lake

One day, Little Suzy goes swimming in the lake with her grandmother. After they get out they go to shower.
“Grandma” Little Suzy asks, pointing between her grandmother’s legs. “What’s that?”
“Oh,” her grandmother replies. “That’s my beaver, dear.”
The next day Little Suzy goes swimming with her mother, and they go showering afterwards too. “Mummy, is that your beaver?” asks the girl.
“Er, yes it is, Suzy. Where did you learn that?” her mother answers.
“From Grandma. But I think hers is dead because its tongue was sticking out.”