AIO - saying goodbye to an ex

TL;DR: Partner wants to say goodbye to an ex they were together with for over a decade and now asks if it's okay for their parents to say goodbye again with them.

My partner of several months wished to say goodbye to their ex. They were together for around a decade, which i appreciate it a LONG TIME. They broke up ~8 months ago. I now realise I should have made sure there was closure and that this was a QUICK turn around, however this is now beside the point as i realise this as a something to avoid in the future should it be relevent again.

Initially this upset me, however I accepted this was going to happen and let it go. They met at her ex's place and said their goodbyes. Fast forward a week and my partner has approached me to ask if it's okay for the ex to go and say goodbye to my partner's parents (with my partner going there too). I did not respond to this well and was pretty negative/upset about it. My partner told me I was making this into a huge deal and it wasn't.

I feel like going back to say goodbye again seems unnecessary, especially because my partner's parents said goodbye to the ex in the past albeit over the phone.

Am I overreacting or being insecure here?