Was it wrong to not apologize to a friend for an "offensive" joke?
I'm the same way. There are times when I don't apologise for my jokes.
If we're the same, then, it's because we're both rude
Telling jokes for the shock value can be fun at times, as long as you don't target people specifically. However, if you cross the line, it is a good idea to apologize.
That joke was just made to be shocking and funny, do you think you need to be like, so PC about everything I do?
Among friends, you are allowed to have more leeway with some types of jokes. But there is always a line one should not cross and I think you did. Apologize to your friend and let them know you did not mean it.