Not I don’t think it’s common in healthy relationships. I believe having crushes happens in relationships were people aren’t content so they seek satisfaction elsewhere, could be innocent crush or something more. I can’t imagine crushes in healthy relationships.

Neither my husband nor I are interested in anyone else but if we watch tv we both might notice that the actor or actress are good looking. We aren’t blind. Same way we’d notice if the cat is cute or flower is pretty. Not like we have particular desire for someone.

Neither one of us is flirty with people. When we out and about I tend not focusing on what’s around me, I am a little hyper, while my husband does look around but it’s because of his safety OCD. He is checking exit signs and doors configurations and if anyone looks suspicious etc lol not checking women out. That’s a non issue for us. Saying that, of course we both talk to all kind of people, coworkers or family friends of both genders. But there is nothing inappropriate going on

But I dated men who looked at other women a bit much yet were jealous if I even turned my head or talked to someone. Not healthy. Needless to say I am not married to those men.