A sarcastic saying used when a person tells another person of something mildly unfortunate that has happened to them, sometimes exaggerated in order to gain sympathy. It implies that the person speaking of their misfortune expects someone to come in playing the saddest song in the world on the worlds smallest violin to correspond with the apparent tradgedy of the situation. Sometimes the person saying this will mime playing a small violin, or try and imitate the sound of a violin.
Jade: Hello, how are you?
Laurel: I just stepped in dog poop and my new shoes got ruined and my feet smell like dog poop, and-
Jade: -Shh... hear that? i'm playing the world's saddest song on the world's smallest violin (mimes playing small violin)
Being defined as losing interest in something, deflating.
Woman: What's wrong?
Man: Well, we were about to make love, but you started talking about your day at work. So now it's Smalling.
Where Visa takes joy from seeing small businesses suffer from cashing in on the high credit card transaction fees compared to using debit. Eerily similar to the German word Schadenfreude, which is to is pleasure derived from the misfortunes of others.