I have no idea, but I'm guessing when he says "Oh that you really meant to kill her" that she only kissed him to bother some other girl. Now he's in love, but she wants him to get lost. Maybe she's crying because she feels guilty? Maybe she accuses him of being in love, but she is the one who is crying, not him. He's thinking she is love, but won't admit it.
I have no idea, but I'm guessing when he says "Oh that you really meant to kill her" that she only kissed him to bother some other girl. Now he's in love, but she wants him to get lost. Maybe she's crying because she feels guilty? Maybe she accuses him of being in love, but she is the one who is crying, not him. He's thinking she is love, but won't admit it.