Holding back, then taking action

In this snippet a character holds back on their reaction to some news, and then they act.

The holding back creates suspense, and the final action creates a release; like pressure builds up behind a dam and then it bursts.

My mother heard me out in silence. She asked no questions. She just let me talk, and when I had finished, she said to our nurse, 'You get them into bed, Nanny. I'm going out.'

Boy(1984)

Arctic explorers loved their sled dogs

Write a hold-and-release moment from your own life.