The Phrase "Live Rent Free" is a modern slang expression indicating that someone or something is occupying your thoughts without effort. This phrase can be used in humor to indicate that you are thinking about something more than you should. For Example, Donald Trump and Kamala Harris have been living rent-free with each other. Indicating at all times of the day they are both mentioning or tweeting each other instead of setting their policies.Lol. Their campaigns are a great example of "living rent-free" because I`ve noticed they are more busy talking about each other and who can diss who better than the real matters.