Yes. I am not sure what age あなた are~ but I do not really think age matters in your question. Now IF あなた were sexually active, and IF あなた thought about this "Crush" while あなた were with a partner (especially if emotionally close to them) then that partner might mind if they knew... although many people probably do this, I am just not sure. (??)
I am pretty consumed によって my bf, but I did fixate on different crushes (usually fictional) whenever I did not have a bf. My lust, desires, または fantasies kinda have to go somewhere & have an outlet. I would think that is normal & my mind drifted theer OFTEN. Some people spend もっと見る time obsessing than others. I cannot say a normal range because I am not a phycologist. I only know that I have an active imagination.
