I tried to post this before, but I don't think it worked, so apologies if this is actually a duplicate. I'm 16, my sister is 19, she has an 18 year old friend who I'm incredibly attracted to (both physically and in regards to her personality) but therein lies the issue. She is my older sister's friend. Not only can I almost guarantee that she will never think of me as anything other than her "friend's little brother", I worry that if I said anything about my interest in her, it could create some awkwardness between my sister and I. This really sucks.