<human>: Summarize the given text in a few sentences.

Basically, I (25/f) have been in a great relationship with my bf (25/m) for over a year. Recently, he and an ex-girlfriend got in touch. Last week, he took a personal week off of work and went to his home state for vacation (where she lives), and naturally, they hung out together to catch up and such. 

He's honest with me about it, he knows it makes me feel bad and made sure to carefully tell me about it. He wants to maintain a friendship with this ex, whom he's known for many years. He assured me there's nothing to worry about. I really respect that, and I don't want to do or say anything that makes him feel guilty (because he shouldn't!).

However, I just can't get over it! It bothers me and I don't know how to make it go away. I think about them hanging out, having drinks, laughing together, sharing moments. Even though it's all friendly, it still makes me feel really sad. She and I are very different, and I knew her a little bit in school (we all went to college together), but I never hung out with her because we just didn't click. I know he values her friendship and I respect that. However, now I find myself acting distant from him because I feel bad and don't feel like hanging out with him now, because I somehow feel like he's hurt me - even though he didn't do anything! He doesn't deserve to be treated like this. I don't want to be the unreasonable girlfriend who makes her bf feel weirdly guilty even though he's done nothing wrong. I don't want him to feel like I'm trying to control him. He can have healthy friendships with anyone he wants. I just want this upset feeling in ME to go away so I can be normal again!

If you have any advice on how to get over something like this fast, please share it!
<bot>: BF has a healthy friendship with his ex, but it upsets me when I think about them hanging out together. How can I get over this silly thing fast so it doesn't damage my relationship with him?