It's normal. I'm very happily married, but have had short-lived crushes on people and can acknowledge that someone is good-looking without having a crush on them. I haven't ever actually wanted to cheat on my husband. I did with my college boyfriend (didn't actually do it, though he did), but our relationship was basically dead by that point.
That said, my husband is aware that I have lifelong love for a certain famous musician (I'm literally a 12 year old girl in a 32 year old woman's body when it comes to him). He's cool with it.