Guys, Is my ex being petty why would he do this?

My ex and I haven’t spoke for weeks it was not a good break up but he didn’t want to speak to me so I finally gave up trying and let go. The other night he sent me a screenshot of his friend inviting Us to a party. He decided to screenshot it to me and it showed his response saying “she’s not my girl anymore but I’ll let her know to come your way” why would he respond that way and why would he send it to me. I’m just trying to move on and it’s like he’s trying to stir things up.
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Thank you for the responses, just wanted to clarify from a males perspective. Just an update he was immediately blocked and I did not respond, waste of time. I’m free!! 😊
Guys, Is my ex being petty why would he do this?
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