It's good that you're sensitive to who is around. But one can't always predict another person's response to certain things, so it's best to remain flexible and forgiving and compassionate if someone is offended by a joke. Everyone has different buttons.

I had a friend (notice the word, 'had') who changed over time into someone who rarely cared whether anyone around her was offended or insulted by just about anything she said. She became very brash and grossly insensitive over a period of time---and I think it was to impress a fairly cynical and intolerant person we also used to know in college. I guess she thought it made her seem cool, to be so heartless about just about everything.

To me, she started to seem like terrible company. We couldn't discuss anything without her shooting it down, being sarcastic and caustic, trivializing even very important issues and feelings I had about them. Soon, she was no longer a friend. It was clear she had abandoned all her principles in order to impress some dude. What complete shallowness, and what a tragic end to a 14-year friendship.

I guess I'm saying, a little sensitivity can go a long way. And people should understand that making dark jokes about many topics really is a coping mechanism that is usually the only thing that separates people from being swamped by uncomfortable emotions about a subject.

You learn as you go, who can handle what. And when. And, if you know you need to apologize for something, when and how to go about it, to save relationships.