"Cut short" ou "Interrupt".
"Juquinha had a knack of cutting people short with a fresh question at the first symptom of rambling."
"If you have the habit of cutting other people short, you should stop that."
"Geez, we do interrupt people speaking a lot, and we will not lend an attentive ear to them!" (Cuidado. Essa foi inventada.)
"Juquinha issued a sharp (nearly inconsequential) rebuke to one of his friends."
Mas... Peraí... Não tenha presa. Relaxe. Espere por outras sugestões.