Its a guy thing you’ll just never understand. 
It gets worse -------- she’s your Sister and Swampy’s Sister too! And he brother was your Brother. I married into either:
a) a very interesting family
b) some strange version of Vatican II
And since you mentioned West-by-God-Verginni --------- back when my one cousin’s daughter was about 3 or 4 or so, she came to me with this real serious look on her face. Now I had lived with that branch of the clan on and off growing up and all of us were close in age and personality so ---------- well, her question was if I was her uncle or her cousin. I was around the same age as her uncles and we sometimes called each brother and she was just confused about it all. Being the person I am my answer was “Well, since I live closer to West Virginia than anyone else maybe I’m your Uncle Cousin”. She got his big smile because everything suddenly made sense to her but about that time I should have started to worry. Because it all made sense to her now. I didn’t. At that moment.
And then the next day a bunch of us (20-25) were at a Old Country style buffet when she call across the room to me “Uncle Cousin ---- come look at these great shrimp!!!” Not a single one of us reacted as if this was anything unusual; the same cannot be said for the other unfortunate 50 or more people also eating there. And once all the clan noticed that the other people noticed, of course they had to run with it. There were a lot of “Aunt Sister” and “Cousin Brothers” thrown around for the rest of the adventure. Just because we could.
We never went back there again. One of a long line of places we’ve never gone back to again.
I invite everyone every year to come up to our family day at Knoebels just to verify something the OW has told some of you in person -------- in big parts of my clan, I’m the shy quiet backward one.