I'm astounded by the amount of horrific negatives in this thread- I'd like to say I'm shocked that very few people followed the original guidelines in answering it, but frankly I'm not. The question, Is it gross, and if so, WHY?
I think I can comment here. Gross is probably not the term I would use. Disturbing, perhaps. I have about 15 female first cousins, and they are all very attractive- good genes. But would I hook up with one? No...no, I don't think so. My reason for this, aside from the totally obvious reasons that come from dating a family member (being ostricized, birth defects, blah blah heard it all) is that we're all just enough alike for it to be creepy. I couldn't look at a blood relative lustiliciously, possibly because thoughts like, "Oh, we have the same nose!" would pop into my head.
But a cousin not related by blood? Pfft, whatever. No blood, no relation.