I know some are not going to agree with me but I think every man is going to look. I'm not saying he is going to wish he was with her, or even that he will think of her at all. It is human nature to look at things that are pleasing to us. Even sometimes without realizing it. I'm not talking about staring. That is different. But everyone is going to glance. Would you walk by a nice car or a pretty flower and not look. A man can have a woman he truly believes is the most beautiful in the world and he will still look.
Even if I'm out with just a friend that is a girl I never look at other girls.
That's rude. I asked her to lunch/dinner to talk to her. I keep my eyes & attention focused on her.
Conversely I was out with the guys for pizza. I noticed this girl that was on a date kept looking at me. He actually turned around to see who she was looking at. I'm sure there wasn't a 2nd date for them.
I kinda felt bad for the guy. That's a big part of why my eyes never wander from any girl & I feel that it's an insult to be looking & make her feel like that other girl is more interesting or prettier.
We all look. If we're straight and healthy, we'll look. It'll make us hard and horny, but you'll benefit from that later. And no matter how much we love our girl, our minds will occasionally wander to the hot piece of ass we saw earlier in the day as we're having sex with our girl.