<human>: I've been with my girl for 5 years and we get along great, but sometimes I feel clueless as to why we are together. I find myself checking out other girls and thinking about why my girl and I are together, but I just brush it off thinking its a normal thing. I don't know if I'm still looking for someone, if this is just a midlife thing or that I'm bored in the relationship and want something more exciting. When my girl and I are together I feel like we don't have anything in common, when I stay at her house I just want to get up and leave because I can't stand the way she acts, it's like everything is about her and I have no say in anything. We see eachother a few times a week and things are good, we go out dancing, out for drinks, to parties and we have a good time, but its only when we spend more than 2 days together that I feel that way. She's mentioned marriage but I'm not sure if I'm ready to get into that with her because I just don't feel like we will make it that long. I don't know if this is just a phase I'm going through or that this relationship isn't healthy. She has also mentioned that her sister is getting married in Spain and is planning on making the trip in September, wants me to come along, but I'm not sure of this whole situation. Please give input and advice as I am unsure how to approach this.

Can you give me the gist of the text in a nutshell?
<bot>: feel like i'm (28m) not attracted to girl (26f) of 5 years, don't know if its me or that it just wont work