"Being creepy" does not represent the situation as well as "Person X is uncomfortable with Person Y's overtures for an increased level of personal contact."
I'm not sure this is it. If I had to give a definition for "creepy", it would be something like: "Person Y's attitude and behavior are making Person X feel personally unsafe (to some degree) around Person Y."
So yes, it does take two to tango, but it's not clear that Person X can do anything about eir feelings, especially since the feelings may be functionally justified at some level (i.e. most if not all examples of 'creepy' behavior actually are evidence that Person Y is more likely to be a threat).
People can do a lot about their feelings. But whether they can or not, the issue of blame is not resolved. That X feels upset about what Y does, and even can't help feeling upset, does not necessarily imply that X is to blame for anything.
As to "the cause" of the bad feelings, clearly it's combination of the X's emotional disposition and Y's behavior, and if either were sufficiently different, the bad feelings would not have occurred.
But we've at least identified one problem in this conversation. You have a different definition of creepy than I...
One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.
There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.
However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender. And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.
Ok, disclaimers out of the way, here are the links:
Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:
EDITED TO ADD:
Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy. (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)