sick joke
1. A joke, story, or anecdote that is meant to be funny but is actually very offensive. He kept telling sick jokes about kids in third-world countries being killed, until someone eventually told him to shut up.
2. Anything that is or seems especially cruel, offensive, or tragic. The government is acting like the $20-a-month increase in the social welfare payments they approved is some huge victory, when in reality its just a sick joke for those who are barely able to survive each month. He worked so hard to sober up and stay off drugs and alcohol, only to be hit by a bus the second week of being clean. It's like a sick joke.