I'm getting worried, I don't want my girlfriend to be friends with her ex.
That does sound worrying. Why don't you want her to be friends with her ex?
She talks about him less like an object, which gets on my nerves.
I can see that you might be feeling a little bit jealous. I think it is okay to tell your partner about your feelings and seek advice. There might be a reasonable explanation for it.
I don't need to talk, I'm going to confront her about all this shit.
I understand that this is all worrying and suspicious, but it could all be a misunderstanding. So I think it's best to approach this calmly so she doesn't freak out or think you are being unreasonable. As long as you communicate properly and tell her how you fel, you will be able to solve this calmly!