a sob story
A sad story told in an attempt to generate sympathy for the storyteller. Don't come in tomorrow without your final project. I don't want to hear any sob stories about how you forgot it at home.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
a ˈsob story(informal, disapproving) a story that somebody tells you so that you will feel sorry for them, especially one that does not have that effect or is not true: Then she gave me another of her sob stories, this time about an argument with her boyfriend.
Farlex Partner Idioms Dictionary © Farlex 2017