not really...if its a rejection better deal w/ it as it is and move on...instead of tryin this bro / sis crap and be friends afterwards? no it just wont work out... it will always be awkward ....and he or she will always have the upper hand...meaning the person that did the rejection...
it would hurt a lot... I mean, you seriously love that person but that person only wants you as a sibling. I'd move on. lol, unless you wanna persist with i t anyway.
i would be annoyed because it means the possibilities of becoming a couple are smaller but then happy because it would mean you can become closer to them and share their secrets etc and you wont argue and break up etc and be good friends
but won't getting closer to them and share secret with them make u hurt even more and they tell u i love this person that person but not you -sweat
usually when they tell u that u r their bro/sis means they are trying to make things clear that u guys are friends and their not interested in you in such a way.
i been through that phase, only this one girl who ever told me " we can only be good friends " . But now, we are good friends, she became my best female friend and i would never make a move on her, long lasting friend ship over relation i guess.
This is a hint from the girls if you have realize, they want to get close to you, (as close as brothers and sister) but they wouldn't dare to spell it out.