Spike has a thread for his tan lines? And WA started it? Bahahaha. Okay. So we now officially live in Bizzaro Land... and in this land, creepy undead types get more sun than Palabra. lol.
I'm working on a theory here, though, and it's not bunnies. See, I am of the intensely pale variety of human complexion that my husband and little goth fanboys the world over find sexy, but that everyone else finds vaguely sickly looking. As a result, I burn easily and pretty darn horribly. Last time I went out in the sun sans sunscreen was roughly two years ago. It was bad. We're talking second degree burns -- with blisters and everything. I still have the tan lines, freckles, and still-pinkish shoulders and upper back to prove it. No lie. I see cancer in my future. The burn I got when I was 19 and forgot to take sunscreen to a music festival left an X-shape (the shape of my, yes, nearly backless shirt) for three years.
The point is that pale skin retains sun damage rather easily. Trust me; I know. And let's say for the sake of argument that William the Not-So-Bloody was a pale city boy pent-up as a clerk in some law firm somewhere in London back when it had all of those nasty gray fogs of cool soot. Isn't it possible that his tan lines are the result of an ill-conceived holiday to Brighton for a little fresh air and sea bathing off the pier? Then a year or so later, he was vamped. The lines, being a part of him pre-vampification, stuck around just like his height, weight, affection for his Mama, and all of those other things that stop changing when you (un)die in the Buffyverse. Fast-forward a century-and-a-quarter, and viola! Spike the vampire has tan lines because William the Victorian wimp went swimming.
Any takers?