If a guy has called a girl his sister, is there any chance of him liking me?

There was this random guy that spoke to me one time and the second time he see me he spoke and added on calling me his sister. This guy and I do not know each other and we never held a conversation together.

I really would like to know what it meant when he did this and was there any chance of him liking me? Would the "good afternoon my sister" be a joke to see what my reaction was going to be?

P.S. sorry I meant to put behavior whether then style if this appears twice.