We are going to keep this one in the back of our pocket

This was spoken by one of the Property Brothers (Drew Scott), referring to a house that was a “maybe”.  I believe this is a mash up of “”in the back of my mind” and “put it in my back pocket”, both meaning to keep an idea to use later.  This one is subtle but nevertheless a nice mixed idiom.  Hats off to Yvonne Stam for hearing this one!