OMG thats such a sweet romantic story happening here yar. Trust me confessing your feelings to a guy is really scary. Take your time and start coming friends first and then start a conversation and gradually you will realise if the person loves you or not.
Wow.. Very interesting! Hmmm lets see... When he looks at u and smiles do the same and gradually it'll b like a routine and since his sister is your friend you can say hi to him here and there..i mean since his sister is your friend it wont seem that wierd and then hopefully you guys can become friends or soemthimg! 😃