talk the hind leg(s) off a donkey
US /tɔk ðə haɪnd lɛɡ(z) ɔf ə ˈdɑŋki/
UK /tɔk ðə haɪnd lɛɡ(z) ɔf ə ˈdɑŋki/

1.
falar pelos cotovelos, ser tagarela
to talk a lot, especially to the point of exhausting or boring others
:
•
She could talk the hind leg off a donkey about her travels.
Ela poderia falar pelos cotovelos sobre suas viagens.
•
My aunt can really talk the hind legs off a donkey when she gets started.
Minha tia realmente consegue falar pelos cotovelos quando começa.