The problem you will have with these sort of questions is manyfold. Trivial 'private' issues like this were rarely written down. Writing was a comparatively unusual activity, primarily written down by men, and usually based on scholarly issues or religious issues. Mostly from people with clerical backgrounds, there was little need for 'rich people' to write much down. It wasnt until long after the Crusades that 'diaries' that may have breached these issues started to be written and even now very few of them have lasted down the ages. The First crusade occurred 500years before your 1600s cutoff and not much personal writing occurred in Western Europe around then. Given that you're no doubt discussing Europe (and not China) then perhaps someone with extensive byzantine knowledge may have some information. But I suspect you're not going to find out much. A good diarist is Samuel Pepys, but he was writing long after the crusades and wasnt much for roaring around Europe raping the women from sacked cities. Overall though really 'personal' style writing is more a product of the last few hundred years.

Attention: this post is (alas) receiving a high number of sub-par answers going on a number of tangents. The nature of the question makes such divergences unwelcome - please only add to the conversation if you are a historian looking to make an informed contribution.

Cheers.

Just want to throw it out there that I find the thread title and subject within to be at odds. Not that men in the middle ages didn't rape, or see prostitutes, however to use the terms interchangeably is not only problematic from an ethical standpoint since both parties are presumably consenting in a prostitute - john relationship, but also it muddies the waters when asking questions since I think no one really has a clear understanding of what it is you're asking.

You might find this book interesting, especially the section on "Wives and Crusading: The 'Canonical Quandry'."

According to Hodgson, "the fact that crusaders needed constant reminders about their behaviour suggests that adultery was a genuine problem." But angering wives wasn't the center focus. Angering God was. Prostitutes (& wives) were occasionally thrown out of the military camps in order to soften God's wrath (138).

Some other interesting points Hodgson brings up:

The wives' potentially infidelity was the focus of discussion during the Crusades, with the husbands unable to fulfill their marital roles came the fear women would commit adultery. Also, wives not wanting their husbands to join the crusades was seen as a serious problem, and sermons/speeches encouraged men to leave behind "the alluring affection of wives" for the greater religious good. According to Guibert of Nogent: "the most beautiful wives were reviled like something corrupt, and formerly more valued than any jewel." William of Newburgh "blamed the failure of the Second Crusade on a large presence of women" (Louis VII was supposedly bewitched by a woman's beauty & couldn't leave her behind).

So seeing prostitutes was seen as bad by the people who wrote stuff down (elite white men). Even having sex with your wife (unless she encouraged you join the Crusades by doing so) was even seen as bad at some junctures.

Interestingly I am just reading the First Crusade by Thomas Ashbridge and completed Runciman's history of the Crusades.

Morality during the first crusade (not very well versed with the following crusades, so will stick to the first) was more driven by a fear of god and this meant abstinence for the most part. Rapes were frowned upon as having sex with an infidel was an act against god.

Ashbridge quotes the Gesteta Francorum and describes an act after the Great battle of Antioch against Kerbogha, he says (I paraphrase as I quote from memory), "we came upon the tents with the women, nothing evil was done to them, only swords were run up their bellies and they were slain".

This act should tell you how the first crusader viewed sin and morality. The act of copulating with a non Christian woman was seen as sin, whereas killing them was seen to be the right thing to do.

In another incident during the First Crusade, women (including wives and camp followers) were chased out of the crusader camp as they were supposed to be agents of sin.

Even Runciman in A History of the Crusade Vol 1 explains at great length on the morality of the crusaders as does Christopher Tyerman in his "Chronicles of the First Crusade".

I guess I am giving you a slightly different perspective, but none of these authors talk about rape as a problem, sacking of cities, outright slaughter, murder...all of these are covered, rape? Not so much.

Edit - This might not be the case in the other crusades, but I have aside from a couple of general history of the crusades type books have not read much about these and hence will not comment about the second crusade on.