Songfacts®:

• Loudon Wainwright married singer-songwriter Kate McGarrigle in 1971 and two years later, they had their first child, Rufus, who became a successful performer himself. The couple separated a few months after the birth of Martha in 1976. Loudon penned this song as an open letter to Rufus when he turned 40.
  
  I knew your mother, let me be clear
  We two were lovers before you got here
  So don't forget that I knew her when
  Love was the means and you were the end
  
  Loudon told us that he wrote the song in the summer of 2013 around the time of Rufus' 40th birthday and he, "wrote it with that in mind."
• Loudon and Rufus have a complicated relationship and a long history of communicating with each other in their songs. Previous Wainwright III's tunes inspired by Rufus include, "Rufus is a Tit Man" (about his son breastfeeding) and the retrospective "A Father and a Son."
  
  Rufus composed "Dinner At Eight" after a row with his father over dinner.
  
  In 2012 the pair collaborated on "The Days That We Die" where they finally come to terms with each other, admitting that neither will ever change.
• This features backup vocals by Wainwright's daughter Martha.