keep one's lips sealed
To keep quiet; to keep a secret; to not tell.
You can certainly trust me to keep my lips sealed about the matter.
ADJ.
clean, full, patient, pressed, sealed, together
She kept her lips sealed about the surprise party until the last moment.
VERB + LIPS
cannot, chapped, escapes, fell, moved, played, poured, see
A sigh escaped her lips as she stared out the window.
LIPS + NOUN
girl, napkin, tongues
She wiped her mouth with a napkin after finishing her dessert.
PREP.
from, in, in, on, with
She kissed him gently on the lips before saying goodbye.
ADV.
firmly, often, slightly
She pressed her lips firmly together and refused to answer his question.