Coworker found my private social media, and blatantly called me out on a post I reposted about the conflict in Gaza. How to avoid political discourse and disagreements on sensitive matters in office?

Hey all, junior monkey here. I work in a finance role at a startup a few years past series C round of funding. Large group, very tight knit, we all have equity. I do my very best to keep my political views and beliefs to myself regardless of how passionate I am. I have a public Instagram account, but my actual name is not in it, so I never worried or cared about people finding it, because one, it wasn’t likely, and two, its my personal social media, so I’ll post what I want and stand by it. Not that I post anything crazy, but I recently reposted a video having to do with the conflict in Gaza (I will refrain from details to not start discourse here), but it was a fact based, and in my opinion, honest reporting on the matter. Well, I’m in the office today, and one of my senior colleague comes up to me and mentions how he found my Instagram and saw that post and thought it was a wonderful time to bring up the topic and ask me, “if I really believe that nonsense”. I became clearly and visibly shocked by the audacity, and told him this really wasn’t fair to do at a place like this, and managed to brush him off of me, but then brought it up again to me before leaving while chit chatting with coworkers. To me, this is absolutely unacceptable behavior, but I’m also open to the idea that I could be ignorant and wrong here, and should be more careful of what I post. Also would like to hear if any political riff raff has happened to anybody else, and how you navigated the situation. What’s utmost important to me is understanding what line of thinking is most responsible and best all around, not necessarily what is fair to my feelings. All thoughts are appreciated, thank you.