When can I use “the last thing~” expression?
Answer from a Native speaker
The idiom "the last thing..." refers to something that you would not want to have happened in a situation where it could possibly happen. You can use it in any situation where you do not want something to happen or be done. Here are a few examples of this expression: Ex: The last thing we need in our school is more students. The class sizes are big enough already! Ex: I don't want to live with my parents, so going home is the last thing I want to do. Ex: The last thing they want is a divorce, but they argue all the time. Ex: Dropping out of school is the last thing you should do. You are going to graduate soon!