Too close for comfort

From time to time my in-laws have debated moving from their sizable home in the Berkshires into a 350 square foot, single room apartment that they own in Manhattan.  

I tried to convince them to purchase the small house next door to us when it was for sale about a year ago, but they thought I was crazy.  Some of my friends and family agreed, unable to imagine living next door to in-laws regardless of the positivity of our relationship, but I had a series of flag-based signals ready to keep...