核心句型：
I don't want to be a third wheel.
我不想當電燈泡。
be a third wheel直譯過來就是：“做第三個輪子”，自行車上裝第三個輪子表示累贅，引申到男女約會時表示：“多余的第三者，當電燈泡”。因此，當美國人說"I don't want to be a third wheel."時，他/她要表達的意思就是:"I don't want to be an unwanted third party on a date."、"I don't want to disturb you two."、"I don't want to be the needless one."。
情景對白：
Terry: I'm going out with Iris tonight. Why not come and have dinner with us?
泰瑞：我晚上要和艾蕊絲約會，和我們一起吃晚飯吧！
Benjamin: You two go on ahead. I don't want to be a third wheel.
本杰明：你們兩個去好了，我不想當電燈泡。
搭配句積累：
①It's your private affair and I don't want to interfere.
這是你的私事，我可不想介入。
②You two haven't seen each other for so long.
你們倆這么久沒見面了。
③You must have a lot to confide to her.
你一定有很多話要對她說。
④Let's ask her out to dinner tonight.
請她和我們一起吃飯。
單詞：
1. wheel n. 車輪
The car wheels spun and slipped on some oil on the road.
路面上有些油，汽車車輪經過時直打滑。
The wheel of history rolls on.
歷史的車輪滾滾向前。
2. interfere vi. 涉入
I wish everyone would stop interfering and just leave me alone.
我希望大家都別再來干涉我，讓我一個人靜一靜。
The UN cannot interfere in the internal affairs of any country.
聯合國不能干涉任何國家的內政。
3. confide vi. 吐露
I knew she had some fundamental problems in her marriage because she had confided in me a year earlier.
我知道她的婚姻存在一些根本性的問題，早在一年前她就向我傾訴過。
He confided to me that he felt like he was being punished.
他向我訴說他覺得自己像是在受罰。