Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:
You need to hear something very important, but you can't. In order to hear, you have to take a key (き) and unlock the doors covering your ears. Go ahead and imagine yourself doing that, focusing on the key.
We are going to listen to the text.
Let's ask the teacher since we don't understand this Japanese.
Listen to me, Amy. This is not your fault. He is not justified in sleeping with someone else just because you two had a fight.