<human>: They're anti-abortion activists and fundamentalist Christians. I'm an atheist, 10+ years now. We generally get along by avoiding politics and religion. Lately, they've been spamming Facebook with articles about the planned parenthood videos. 

I generally ignore Facebook, but then my wife [27f] mentioned that my sibling [30f] posted a particularly egregious article that essentially said that anyone who supports planned parenthood is a Nazi. So, this baited me into making a few sarcastic responses (my point being that anti-abortion people regularly judge someone's worth based on how close they were to the anti-abortion platform), which in turn caused my father [55m] to chime in with angry references to slavery, Nazis, human dignity, etc, and a reprimand that family should have loving and interesting discussions. I didn't respond.

It's just been eating at me in the month since. I haven't apologized for using sarcasm. I'm not exactly sure what I want to do going forward. I get angry when I think about it; I don't think that 'discussion' was loving or interesting before my entrance. It's distracting me while I'm at work, I'd like it resolved. Do I write a letter? Do I apologize? Do nothing? How have other people handled situations like this?

Give me a shortened version of the text
<bot>: sarcastically responded to fundamentalist family's outrageously simple-minded Facebook post, causing conflict with parent, been eating at me since.