run one's mouth
• talk excessively or indiscreetly.
• "he just keeps running his mouth until I get really angry"
Similar:
talk incessantly,
talk a lot,
rattle on,
go on,
chatter on,
gabble on,
ramble on,
yak,
gab,
yackety-yak,
yap,
yabber,
yatter,
rabbit on,
witter on,
natter on,
chunter on,
talk the hind leg off a donkey,
slabber on,
run off at the mouth,
mag,
twaddle,
twattle,
clack,
