Should I invite him to my party

I was gonna post this in r/makemychoice but I wouldn’t let me so hopefully it fits here.

I’m hosting a small Christmas cocktail night with a mutual friend, and my ex (who treated me poorly) will be there because he’s close with that friend. We ended things because he treated me badly, but we still end up around each other socially.

This semester I also got close with another friend group which he claims is his friend group however they do not consider him a close friend. There’s a guy in that group I like, and my friends think inviting that group (3 people) could help me get to know him better. The problem is one of the girls in that group is someone my ex had feelings for in the past and confessed his feelings for her again after we broke up she ultimately shut him down and he’s upset , and he has told me before that he doesn’t want me spending time with them out of fear I will say how he treated me and ruin this perfect Christian image he puts on.

I feel guilty because I still care about him and I don’t wanna invite someone who might make it uncomfortable for him but I also want to move on and meet new people. Should I invite that group or keep the night small?