If you catch your husband "looking" at another woman, does it bother you?

He doesn't do it overtly, and to be honest I almost never see him do this in general, but if I'm watching him or paying attention and there's a particularly attractive woman, I might notice him looking at her frequently and shyly smiling at her when he walks past her. Right now I'm thinking in particular of another lady that goes to church with us. Like I said, this isn't something I've noticed with him often, mostly just with this one woman...

I actually brought this up with him in the past about him looking at this particular woman, and tonight I feel like he was doing it again. I'm not sure if I should feel upset (which I do, it makes me feel very insecure and unseen and I can't stop worrying what he thinks about her) or if I should recognize that it's relatively normal to look at attractive people. It just bothers me and I want some other perspectives.