I know what you mean and I still go through that, even though it's been about 2 1/2 years since I first told someone what happened to me.
I'd love to say that time helps, but it hasn't for me. I guess it just depends on your circumstances, outlook, quality of therapy etc.

As for when the subject comes up, I up and leave. It doesn't matter where I am. I'm not able to hear about it, read about it or anything because it still triggers me terribly.
I have one safe person who knows that it's not a good subject to talk about unless I specifically mention it first- maybe you can do that if you have a close friend or someone who you are comfortable with?
And when I hear jokes about it, I get angry. Super angry. People who do that are either 1- ignorant, 2- perpetrators, 3- children/ teens/ immature adults who were never taught better. I don't usually confront the person, but when I do, my voice gets deeper and sharp and I can become pretty terrifying (which is contrary to my usual nature). I let them know that it was wrong and that if they ever say something like that again I will never see them again. (or in my family's case, I said I would leave and never come back regardless of my lack of money and life skills. it might not be reasonable to give them pressure like that, but I didn't mean it in a threatening way, I meant it like 'I will never feel safe here again if you say something like that') Because people who joke about that and don't try to understand my reasoning are people that I view as dangerous.

Something that might help you get better at expressing it/ staying calm after you express it- draw/ write angrily to the person who did that to you. Another thing that seriously helps me feel better when I'm having a panic attack or a flashback is to change what happened in the memory I see. I'll visualize myself getting up and leaving, or creating an ocean between us and putting them on a small island, etc.