Me and my girlfriend of the last 3-4 months broke up a week ago, and she works with me (I know not to do this) so we still talk occasionally and yesterday she mentioned that her last ex called her from someone else's number (bc she had blocked his). She said that he was really sad because one of his friends died, but that she had blocked him bc he was a dick to her when she broke up with him a few months ago. She said that she just said something generic when she realized who it was and hung up.

My RP-fu isn't the greatest, but I think she told me that as a way to demonstrate (self-validate) that her past exes were still hung on her even though I'm not even talking to her except about work stuff.

I have no intention of getting back with her as I find her to be spiteful when angry, but for informational purposes what would be the best response to that. I didn't even acknowledge what she said about her ex, I just said "I'm sorry I yelled at you" (the situation which led to our break up).