Need boy advise help please?

Ok. I really like this boy named Garret. How can i tell if he likes me back when we are alone he is pionate loving sweet caring kind and he is only like that if it is me and him or if his sister or friend Daniel comes around but when any of his other friends come around his attitude completely change he becomes a complete *** and I really do love him he has always been there for me and has helped me through all my hard times i mean sometimes we act like a complete couple but we are not one. what should i do? Does he like me?