He probably does think you are the most beautiful woman in the world; you are his wife. Obviously a young late-teen, early 20 something year old with a cute little body in a bikini appeals to most men. Unfortunately a lot of people put way too much emphasis on looks and appearance than what a person has intellectually. Stuff on the Internet like that is so easy to access; just type in what you want, and in a few seconds, there it is, up on the screen for you to look at. I agree that it is bothersome and probably makes you feel like you are not good enough. I am sure that you are. This is something that a good majority of the men, even in a married relationship, look at. At least they are just nameless pictures on a screen, nothing more. If these girls want to degrade themselves by being on the Internet "posing" for all of the men of the world to see and stare at, then they don't have much going for them. I wouldn't worry too much about it if I were you. Be youself and be proud. And remember, if you feel like getting a little vengence, there are plenty of sites with young studs on them also. See if he likes the idea of you looking at "them".
I guess I have to ask -- why do you care? Are you insecure in your relationship with your husband?
I have been married to only one single woman for over 35 years. I love her dearly and hope she loves me as well. During that 35 years I have frequently used **** magazines and later web sites to seek stimulation and gratification. You see, my sexual drive was far stronger than my wife's. She got tired of me bugging her for sex and I got tired of being rejected. Part of the way I coped with the situation was that I adjusted my demands downward so as not to bug my wife. This helped her feel less pressured. However it did nothing for my strong sex drive. **** and self-gratification filled the gap for me and kept me from going astray with other women.
A lot of other things could be going on but I can almost guarantee that in some way, your husband is not getting from you and your relationship something he needs. Looking at pictures of hot young women fills some need. The two of you need to talk about this. You need to ask him in a non-accusatory way, why he is doing this. Don't pressure him to give it up as that will either drive him into hiding or on to other means of filling his needs and releasing his sexual tension.
One thing you need to know is that for men, sexual release is a means of releasing general tensions of life and work as well as sexual tension. I do not believe this is the case for most women who seem to avoid sex when they are under tension.
Another thing that may be going on is this -- at the age of 53 he is beginning to experience changes in his sex drive and may also be experiencing changes in his sexual health -- ability to gain and keep an erection. These changes cause many men to seek ways to stimulate themselves sexually in ways that they at one time required no special stimulation. These natural changes can cause a man to question and worry about his "manhood" and looking at pictures stimulates him and helps to reassure him that he is still a potent sexual male.
I'm living with a man in his late 60 and I've discovered that he looking at teenage girls private parts on Internet... I have to say I'm very concerned about this as I have a few very pretty young nieces... What's wrong with this man I really don't understand...