I guess I overreact a lot because... well, because sexuality and lust is one of my own personal struggles. It aggravates me to no end that if I merely point out what the church teaches, I'm labeled a puritan or as someone who wants to "keep women in clothes like on little house on the prarie" (as Serge likes to say about me). I never said that sex was dirty; though if I did I wouldn't be unorthodox, that is a perfectly acceptable Orthodox answer. I never said we should avert our eyes from beautiful things; though if I did that wouldn't be unorthodox, that also is a perfectly acceptable Orthodox answer.
The funny thing is, these discussions today revolve usually around two types of people. One type knows what the fathers teach, and struggles hard to follow them, though for the most part fails. The second type doesn't have a clue what the fathers teach, and just assumes that it can't be all that different than what he or his priest thinks. When the first type (like me) tries to explain to the second type the Orthodox position, both end up overreacting. The second type thinks all of a sudden that the person is saying we can't notice beauty, that "attraction" is a sin, and so forth. By the second type overreacting, this leads the first type to overreact as well and go into a defensive mode, beacuse not only is he not saying what the second type said he was saying, but even if he was this would still place him perfectly within the acceptable arena or Orthodox beliefs!
The fathers do not say we cannot look at beauty, they just cautious against it. To look on beauty is to lose focus on God. The fathers followed faithfully those passages when spoke of "meditating on God day and night" and "pray without ceasing". All the things of this world are possible distractions to that, which would lead us away from God; those things we subjectively see as "beautiful" can do it even more so. This is not to say that something beautiful cannot be beneficial or draw us closer to God by thinking about his glory, but it's dangerous and we must guard our hearts.
Concerning the opposite sex, again, I don't say it's wrong to notice that someone is pretty. We can, for instance, notice that a baby or child is pretty or handsome with no sinful or sexual aspects to that thought; we can do the same thing with adults. However, in our lust-crazed society, this is very difficult. Certainly we should not go out looking for beautiful people, or line them up for everyone to stare at. Saint Tikhon of Zadonsk said that we should stay at home unless we needed to go out, because whatever good we would have at home would be lost be going out among people. Most of the saints follow along this line of thinking. It's not that beauty is bad, it's just that worldly distractions are dangerous for us spiritually. No doubt if I had said we should stay at home (rather than St. Tikhon) I would be labeled a puritan or something similar.
To think about someone in a way other than as a sister in Christ is a sin. It's lust, and according to Jesus, he who lusts has commited adultery. Lust does not just mean thinking about someone graphically, though. A good way to judge whether our thoughts are unChristian is to take our thoughts that we are thinking about someone else, and then imagine that someone else was doing the same thing to our wives, daughters, husbands, boyfriends, etc. Would we be ok with that? Suddenly that "innocent little look" seems not so innocent, when you decide that you wouldn't want others giving that look to your wife. Suddenly thinking "what a nice chest" or "what a nice butt" becomes not so innocent, when you decide that you wouldn't want some guy thinking that of your daughter. Think about others as you would have them think about you and yours.
I'm also a bit confused about the whole "well you can't go by what monastics say" type of thinking (and I'm not saying anyone here said that, but it usually does get brought up at some point). According to Orthodox epistemology, the more one gets cleansed by God, the more they understand--human things as well as divine things. It doesn't matter that someone is a monk. Most of the saints were monastics, but then most of the saints understood society and marriage better than people who were actually participating in society in marriage. Knowledge does normally come from experience, but God grants knowledge to saints that lets them look into people's souls, know what they are truly thinking, know when they are approaching, able to heal diseases, they understand the mysteries of the universe and human psychology infinitely better than we... and yet sex mystifies them? beauty confuses them? This is not Orthodox thought, this is a belief whose seed was planted by the reformers (especially Luther) and has not permeated western society in a quasi-anti-monastic sentiment. They are confined to their monasteries: they do their thing, we'll do ours; they can't possible understand us, nor we them (so the idea goes). But it's wrong.
The Bible said that Jesus was tempted in all things like us. Did that mean he experienced all things? Did he experience child birth? Did he have other feminine issues? Was he tempted to sleep with Mary Magdalene? No, he wasn't tempted to do any of these. And yet the Bible says he knows our temptations in all things. How, did he experience every single last one of them? No, but God grants knowledge to those who seek and ask. One needn't experience drug use to know it's dangers or temptations: even in a wordly way we can understand things without experiencing them. How much more so is this true when it is God who gives us the knowledge! What, will we say that God's grace is unable to make up for the learning experience of action doing something? No, even monastics who have never stepped outside of a monastery (ie. been there from birth) can--if they seek out the knowledge and struggle and work hard for it--attain to a much higher knowledge than those who actually live in the world and do things that non-monastics do.
This isn't to say, of course, that we should follow along monastic literature and apply everything they say. There's a good reason that many priests caution against reading the Philokalia and such books: because we usually don't have the spiritual discernment to know when and why to apply teachings, and when to avoid them. Monastics normally took a maximalistic, seemingly dualistic approach to most worldly things. They "despised the world" (understood aright). Certainly we should not follow them in all this. Yet, the psychology in their sayings, the basic spirit, is applicable for all, even if the actual command or action isn't. Amazingly, even heterodox authors like C.S. Lewis seem to be able to notice this; his Screwtape Letters for instance is filled with the brim with sound psychological knowledge, most of which could find direct support among "the monastics" of ages past. The problem isn't the teachings, the problem is the application, and knowing how much is too much in each of our individual lives.
But at the very least, we are all called to modesty. We are all called to non-judgment. We are all called to go "further up and further in," which takes more dedication than a couple hours on Sunday morning, but is a full time discipline. It means you can't do things you might like to do. Sorry, that's how it is. We need to prioritize our lives and see what is most important to us, and what is of benefit to us spiritually. Somehow I fail to see how going to the beach to purposely look at guys (though there would be other reasons to go I'm sure) or watching a "swimsuit competition" as part of a 'beauty pageant" is beneficial to us. It seems to me that, even if you aren't effected yourself (which I think formost people is impossible, it certainly would be for me if I saw an attractive girl in a bikini) you are still feeding into their pride and vanity. You are making it possible for them to continue on as they are--which may be on a very wide road, and not a narrow one. If this line of thinking offends you, then maybe it's because it came from a monk, for this is roughly what Saint John Chrysostom said of the distractions of his own age. Only, Saint John was much harsher in his judgement, whereas I'm trying to be restrained.