I do it too, but waaaaaaay more discreetly than he does, lmao. It doesn't bother me for him to look at other women when we're out; he usually invites me to look for myself if he finds any of them attractive.
That might be a part of why it doesn't bother me. I already know where his focus is and that's enough for me.
Bi poly female parent in a LTR.