be laughing out of the other side of (one's) mouth(redirected from are laughing out the other side of their mouth)
be laughing out of the other side of (one's) mouth
To be experiencing a drastic change in one's emotions, often in a short span of time. A: "I thought your mother was happy that we're getting married." B: "Me too, but now she's laughing out of the other side of her mouth, and I get an angry phone call from her every day."