Was going to check out the rest of your Gallery before choosing my Faves (there's sooo many to choose from!), but this one's raw sexuality, intensity and style just got to me first. A really hot, but not raunchy, piece of artwork. I love all of your work with these guys!
I've never had one either. But I heard that they put them in anime so they don't have to show boners. It's possible that people can have them if enough blood rushes to their heads in exreme excitment, I guess. Maybe it has to be insanely sexy. Whether or not they're true, nosebleeds make good reaction emoticons!