It may be somewhat inappropriate, but I have to talk about this short story （在明孝陵乘涼 by 魏微）at a seminar:
I have been taught "我喜歡你", when said between people of opposite sexes, usually means a romantic kind of fondness. In this story it seems the girl likes her brother in a not so innocent kind of way. Is this clear to the brother, when she uses
or is there enough room to interpret it as innocent fondness among siblings?