have no heart for (something)
To not have the emotional resolve (for something); to be unable to do something, especially that which is or seems callous or unsympathetic. I just had no heart for a deep conversation about how I don't love her anymore. How could you fire someone the day after their father died? I would have no heart for that.
have no heart for
Also, not have the heart for. Lack enthusiasm for, as in After the dog died he had no heart for taking long walks, or I should go through the family albums, but I don't have the heart for it. [Mid-1600s] Also see heart in it.