I haven't seen it for a long time, but girls wearing white ankle socks used to do it. Especially if they had black stretch pants on.

Also, like Lou, I often end up really horny while reading. Sometimes I'll just stop and get myself off so I can concentrate on the story again.

__________________
Put me on wheels and I'll turn tricks.

Clever? Nah, I ran out of that years ago. But if you find this, let me know, k?
"The road goes ever on..." ~ Tolkien

In memory of my friend skip...
Go then, there are other worlds than these