Here are the full lyrics: Http://www.azlyrics.com/lyrics/taylorswift/blankspace.html She's talking about a guy she is attracted to, but she suspects he would be trouble. "Magic" and "heaven" describe how appealing he is, but "madness" and "sin" suggest that a relationship with him might be dangerous. It's " (I) saw you there." "You look like my next mistake" means she wants to be with him, but it would be a mistake. "Rumors fly" means people gossip about him/her. "If the high was worth the pain" means if the good parts. Is the fun and excitement of the relationship,worth the pain or trouble of a potential break-up. To make the tables turn means to change a situation so that you now have an advantage over someone who previously had an advantage over you. To second guess means to doubt or criticize a decision you've already made, so to keep someone second guessing in a relationship means to keep them wondering whether the relationship is a good idea.