Is my ex being petty

My ex bf got with a really close friend of mine recently. I found it funny though how I started (unintentionally) dating a friend of his a while after we broke up. My ex had asked my bf if it was true that we were dating and when he told him that we were he like shunned my bf out of his life lol.

Then in October I see that a friend of mine that I’ve been close with from middle school is asking me if it’s okay that she and my ex are talking and I’m like WOW this is so coincidental. Anyone think this too?