Throwaway acc cause I am pretty sure some of my friends use Reddit.

So, I (M21) am in a relationship with my girlfriend (F21) for quite some time. I enjoy spending time with her and we are somewhat close. When I first met her, I knew she REALLY liked this animated show and I didn't mind listening to her talking about it. We were friends for some time and then decided to start dating. As it seemed to me, this relationship has brought a lot of positive things into our lives. I would even say that it's the first time I would feel that I am truly happy with my life. I really thought of her as my future wife. She even brought up the idea of marriage herself, and I said that if things will go as good it will probably happen but I am not ready atm (because of financial problems).

Here is where my problem lies. Today I decided to scroll on a social network I rarely use. Then I remembered that my girlfriend had a page on this platform and decided to check what she was posting. After scrolling for a couple of posts I saw a picture of a character from the show she liked with a caption "HUSBAND!!!! Most beautiful man ever". It instantly gave me an ick, cause she sometimes would call me her husband. I knew she liked that character but not to this extent. After further investigation I came to a conclusion that she was obsessed with him for about two years. I want to clarify that she didn't hide this obsession from me, I just didn't understand the scope of it. I don't want to confront her about it cause I don't think I should try to change who she is and saying something like "Don't say that, it upsets me" wouldn't change her thoughts about that character. I don't really know what to do now, cause I can't look at her the same way now. It's not a deal breaker for me, but it just feels weird. Is it normal for her to be obsessed with a fictional character at this age?

P.S.: Sorry if this reads like shit. English is not my first language