look like the cat swallowed the canary
to have a knowing and self-satisfied smile on one's face; to be pleased with oneself, often because one has done something which one knows was wrong but which was very enjoyable.
1. when the teacher came into the classroom, the students sat there looking like cats that swallowed the canaries
2. don't trust karen, she looks like the cat swallowed the canary...i know what you're up tp karen!!
: look like the cat swallowed the canary
2. don't trust karen, she looks like the cat swallowed the canary...i know what you're up tp karen!!
: look like the cat swallowed the canary