I work with this guy, and also have him added as a friend on facebook. Every time leaves me a comment or message (which is often...) he'll leave me a picture of some overused lolcat, call me myname-san, or just generally be annoying as possible. What's a way of telling him to knock it the fuck off without causing work drama? Extra points if it dissuades the crush I suspect he's starting to develop for me.
If you don't care, tell me about annoying habits your coworkers have.