I'm going out on a date with my ex gf and my ex cheated on me and tried to get back with his ex gf
How did they manage to happen?
I really liked her and I wanted to give them a second chance with someone else.
That sounds like a huge mess and I'm sorry that all happened, but you shouldn't keep getting involved with exes. You need to move on and stop setting yourself up for all the potential hurt.
It's fine, I wasn't really interested in her and I just wanted to fix them up.
I think that sounds a bit noble. It might be better to just move on and stay friendly with your ex.