Will and won't. Because I as a girl I also like to look at good looking ladies even will share to my boyfriend to see, "wow this girl is good looking ah", completely for the purpose of sharing. It just so happens that when I meet my boyfriend's favorite type, he'll agree and I'll be very happy.
BUT!!! If one day two people are chatting nicely and he suddenly sends me a video of white skin and long legs and tells me that this looks good, I get angry. Suddenly not particularly angry kind of angry, is a little angry, really a little. I wonder if he doesn't like my type of girl.
I don't think the problem is being petty. I think the problem isn't that I'm not angry, but that I'm angry because of my sense of security and self-esteem. The long distance relationship itself is not secure enough, not to mention the attention is on such a hot babe. You can't say he is not devoted to your feelings, after all, he can't access these beauties. Your concern is that his heart is still alive in case he meets such beautiful women.
If so and so happens, instead it's easier isn't it? Litmus test. No need for you to dwell on it over and over again like this. As for whether this is a necessity for men, I think it's overstated; it's true that one favors the opposite sex in terms of beauty, but it's not something one would focus on in this way in every situation.