look as if butter wouldn't melt in (one's) mouth
(redirected from looked as if butter wouldn't melt in his mouth)look as if butter wouldn't melt in (one's) mouth
To appear innocent or reserved in certain company, when in fact one may have the opposite demeanor. Sure, he looks as if butter wouldn't melt in his mouth when he's around people he doesn't know, but stay a while and you'll see what he's really like.
look as if butter wouldn't melt in one's mouth
Fig. to appear to be cold and unfeeling (despite any information to the contrary). Sally looks as if butter wouldn't melt in her mouth. She can be so cruel. What a sour face. He looks as if butter wouldn't melt in his mouth.