Why did he block my parents on Instagram?

That guy and I were together for two months. He never trusted me and thought I was seeing someone else.
A week ago we had a fight, he accused me of being with another guy and blocked me on Instagram. Now, when I went to my mom's Instagram to look for his profile, I couldn't find it. I also tried from my dad's profile, but it didn't work. I entered my friend's account and I see that he has Instagram, he didn't delete it, but he blocked mom and dad. Why did he block them when he doesn't even know them? Nor did they follow each other on Instagram?
Why did he block my parents on Instagram?
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