Its part of the game 我在扮演妈妈

Mother: Mary, why do you yell and scream so much? Play quietly like Eddie. See, he doesn't make a sound.   Mary: Of course he doesn't. Mom, it's part of the game we are playing. He is Daddy coming home late, and I'm you.   妈妈：玛丽，你为什么这样大喊大叫的？ 为什么不能像艾迪那样安安静静的玩儿呢？你看艾迪一声儿都不出。   玛丽：妈妈，艾迪当然不会出声了，因为我们俩正在玩爸爸回家迟到的游戏呢，他扮演爸爸，我扮演你。