My(26F) boyfriend(26M) has a weird habit

I’ve(26F) noticed something about my boyfriend (26M) that’s been bothering me, and I’m not sure if I’m overreading it or if it’s a red flag. Whenever he’s around women(more often the pretty girls), he subtly changes his behavior.

He doesn’t stare or do anything super obvious, but if he ends up talking to one, his whole demeanor shifts, he straightens his posture, his tone gets a bit more charming or performative, and he starts acting like he’s trying to make a good impression. One other thing that I’ve also noticed is that he would immediately adjust or straighten his hair when he notices an attractive woman nearby, like they just have to appear in his eyesight.

I brought it up to him before, but he denies doing it and says I’m imagining things. Still, I keep seeing it happen, and it makes me feel uncomfortable and kind of disrespected, insecure even.

I don’t know if this is something I should let go because it’s normal human behavior, or if it’s a sign that he’s not being considerate of me. Has anyone else experienced this? How did you handle it?