Moira Rose - BéBé It's Cold Outside Color Changing Mug - Reveals Secret Message w/ Hot Water - Schitt's Creek.
The mug starts out a glossy black color. When hot liquid is added the brilliant color message appears and the mug turns white! Surprise your friend with a secret message.
To see it in action click here! https://youtu.be/XxcNhS8f1cQ