dating cousins was common practice in most of the world for thousands of years. furthermore it is still practiced today in some places. And finally evidence suggest that there is actually a lower risk of genetic defects in children born of close relatives (not siblings).
I find it kind of suspicious that Braeburn doesn't have any inner thigh sparkle. Would you mind explaining what happened to Braeburn's apple orchard, Mr. Gavalanche? Also it may just be me, but I think Braeburn's is trying to imitate Applejack in that "So Much Pony" gif.
Overall this is pretty dang a'dawwable, once you forget that they are cousins....
I thought about it, the inner thigh sparkle. But in the scene with them cuddling it just seems like it would be way too blatant (since his legs are splayed), and it would have killed the mood I was going for. I'll probably do an edited version with the sparkle, but that'll go up on the tumblr.