@shipsnotdrugs From what I can tell from my friends who ship it, they often ignore the relationship - there's lots of AUs for Wincest. It's more about the characters and what they've been through together than what they were born. Plus, they can argue their brotherly relationship doesn't come into the show that much - after season 2 or 3 their normal behaviour is much more friends than brothers, and the brothers thing only comes into play when needed. So... Meh.
I personally still find it messed up.