I do have a dark sense of humor, which has gotten me into trouble before. A group of us [my work colleagues at the time] had been up since 5am blowing up balloons for a campus event. Some of the balloons had started deflating by 8am (and they needed to be up at 8), and it looked funny to me. Someone joked that the balloons had "issues" and I topped it by saying they had a disease. Worse, I named the disease: They had "BAIDS" (Balloon AIDS). I thought it was funny and a few laughed.
Others were absolutely appalled and found the joke "in poor taste."
Which...actually, I didn't see. And I have to be honest, yes, someone close to me *did* die from AIDS, but I think he would've seen the humor in the joke.