To me, the person, most likely a boy or man, is asking to know if someone is merely dating him, waiting for someone else to come along, or it could be the beginning of a true relationship. Perhaps she has shown signs of reluctance, but she keeps spending time with him, and has even shown she liked his touch and talking to him. When he says, "someone like you," he is expressing far more than the words say, such as, "You are perfect for me." Yet he doesn't want to prolong this relationship if it's something she'll soon cross off her list. The lyrics are very careful and precise, and seem to be asking if there isn't someone in her past who could easily return to be the one for her.