Family wants to meet abusers children. Am I being unreasonable in not supporting this?

So my abuser has been excluded from family events since for a while. He has subsequently had 2 kids who are now in their early teens. My family now was to include these teens in family events. Look I have nothing against the kids. They are not the perpetrators but I am still so deeply effected by the decade of abuse I suffered at their dads hands. I know too that there will be questions that will be asked that I don’t want my daughter hearing about etc. and how long will it be before dad goes from dropping them off to being included. I have always felt like he was excluded just because it was the thing that had to be done rather than from a place of outrage.

What I want to know is am I being unreasonable for not supporting this? I feel like I’m going to lose my family because they will include them whether I approve or not.

I actually feel really stupid just typing this.