Am I wrong for feeling hurt?

[RaidenGTO]

I've been with my partner for over a year now. We have a fantastic relationship & have never had cause for concern in any aspect.
However, whilst doing something on her phone last night, with her permission I might add, I came across messages between her & her ex. Nothing really untoward, just general chat. When I confronted her on it, she apologised, said she didn't really think anything of it & removed him from her account. But the fact that she was still in contact with him & thought that it was ok to be, has left me feeling hurt, partially betrayed, & lost.
I would genuinely like to know if I'm wrong for feeling like that. Feedback would be greatly appreciated.

I'm friends with two of my exs on facebook. They came to our wedding. I'm also very good friends with one's gf. She knew about me and ex and like DH doesnt care. I also have an old FWB on facebook. DH knows, and also knows nothing untoward will ever happen. We're both with other people, and both parents. Mainly we chat about peppa pig. DH has an ex on facebook and chats to her. He also has a coffee sometimes with another, though they have a child together so that is a bit different. I think you need to work on your trust issues though as they will destroy your relationship. Your mrs did nothing wrong and took your feelings into account straight away. As PP have posted it's just about trust. Hope you get everything sorted.