Inviting a family members ex help

I need some advice. Should I invite my brothers ex to my wedding. Background: My brother and I are very close (or we use to be, he can be distant when in a relationship ). He dated a girl for four years. Her and I became very close, but she and my brother were awful together (loved her but HATED them together, They broke up a few times and tried to make it work, but it didn’t (thank god they gave up). Her and I stayed friends and my brother seemed ok with it. She started dating a new guy months later, who was actually my now fiancé’s best friend. She was the one who actually pushed me into dating my now fiancé. So we stayed close for the following years . So her and my fiancé’s best friend broke up after 2 or so years of dating (it’s still pretty fresh). My brother on the other hand began dating someone perfect for him about a year ago and they’re expecting a child in July, two months before my wedding. There was no problems with my brothers ex and I being friends until his new girlfriend came around (I’ve also become very close to her). I’ve made it clear to the new girlfriend that my brother would never get back with his ex/ she doesn’t ever want him back either, and that there is absolutely no worries. A couple months ago there was an issue brought up by my bros new gf about the ex and I being friends but we squashed it and now idk what to do about the wedding. There was a discussion about my wedding list and my brothers ex was on it. In my mind I’m thinking “well both parties have moved on, ones about to have a baby so there shouldn’t be a problem... I mean it’s been 3/4 years since they dated!” ... the other hand I’m thinking “ I don’t want the newer gf to be uncomfortable and leave early taking my niece and brother”.....I don’t want to hurt anyone, I want to invite both parties but am worried my brother and his gf and my niece won’t stay or that the ex will completely blow up if she’s not invited! Help!!!!