If you want to catch fish, don’t throw your net into the bathtub.
Gee, this isn't like I imagined it would be in the bathtub.
I knew we were having problems when you put those piranhas in my bathtub again.
I have a beautiful, big bathtub.
I like to read either in motion or in water... I am happiest reading in the bathtub.
Being in a floodplain is like sitting down in a bathtub.
Nothing changes instantaneously: in a gradually heating bathtub you'd be boiled to death before you knew it.