It all comes down to what you believe makes someone beautiful.

To post a slightly-related quote from TTS, "You must believe in the heart of the cards but that is not the only muscle you must believe in! You also believe in the lungs! The Kidneys! The Arms. And the [i]FFIIIIRRRMMMMMM[/i] BUTTOCKS!" 

In short: if you think its eyebrows which make someone beautiful and you believe in that, then yes by all means if fine to be sexually attracted to eyebrows. I can't fathom how you'd actually fuck them tho and I've seen a lot of shit from Japan. I don't think THEY'VE done eyebrow stuff which is saying somehthing.