<human>: I've been in a relationship with my girlfriend for 5 years. I love her, things are going just fine. I feel comfortable around her. The honeymoon phase is over. I believe this to be normal. However, whenever I see a beautiful girl passing me by, I sometimes wonder if it would be more fun to date her/do things with her/ have sex with her. I can get really happy when I notice a nice girl and she notices me back. Is this normal?

I like the thought of being together with someone all my life, but I wonder if it's more normal to have different partners throughout a life time.

Can you summarize the given text in a few sentences?
<bot>: I sometimes wonder if my SO is the one, because I enjoy it immensely if I see a beautiful girl and wonder how it would be to have a relationship/date with her. Is this a sign that I'm not happy?