She Is On a Trip

I used to work at a school where children were always saying their mother or father were on a trip. It was curious to me that one child's mother was always on a trip. Her teacher told me this is what the children say when their parents are in jail. I had no idea until that time that this was a thing. It is widely accepted, and well known in this community what "on a trip means". I believe I was the last one to know. Glad to find out, I stopped asking them when their parent would be home.