If a joke is funny, I'll laugh at it. Even if it is about something as horrible as rape or whatever. Humour can be found anywhere.
I don't really understand the humor in rape jokes because I know someone who has gone through it and it really traumatized her for life.
Of course, sometimes it does take something horrible happening to someone you know to open your eyes to how horrible something is. I shamefully admit I used to make all kinds of jokes about domestic abuse, then someone I know ended up in an abusive relationship. It opened my eyes, that's for sure. While I would probably still laugh at a domestic abuse joke, provided it was funny, I've never been able to tell a joke about it since then.