Person A is in a grocery store, the cashier puts everything in bags, and then puts all but one of those bags in the shopping cart. Person B comes along and when nobody is looking takes the bag of groceries that was left. Later Person A realizes that he doesn't have everything, but just assumes he left it in the store. Etc. Etc.
Also, to the people who say that this is just Twin hate, you're wrong. I liked Trey & Lexi before, but not anymore.