Am I overreacting?

I have a best friend, we’ve been BFF for about 4 years now. I know the last two relationships he was in, he knows my “history” he’s always wanted more with me but I was always so scared to mess up our friendship well recently I just told him I couldn’t burry my feelings anymore and I want to pursue with him.

The things is.. we just started about 2 months ago and his last recent ex, we just never got along. She’s so immature, it was always “competition” before we started “dating” they were still hooking up, I’m not jealous type at all. Idc about his other ex’s or girls he messed with but the fact that she throws a fit when it comes to him and they were just fuck buddies. I don’t want him having contact with her.

Idk if this is me overreacting? I trust him to the fullest, I know him pretty well I just don’t like the fact that she doesn’t respect what we’re working towards.