I notice attractive women 10x more when I’m out with Boyfriend

I realize I can appreciate beauty in other woman when I’m by myself and not feel intimidated by it. But when I’m with my boyfriend out in public I notice it ten fold and feel very vulnerable and insecure cause I know he’s going to notice her or look back at her and try to be slick with it. He never stares but it makes me think of what he does when he’s not with me and an attractive woman is around. HELP.