In chapter 9 if you don't get into a relationship with Lena, you'll have another chance in chapter 12. For it to work, Ian cannot be dating Cindy or Alison and Lena must choose that she wants to be in a relationship with Ian. Also, for you to not get the crisis event, Lena must not sleep with anyone at the club in chapter 11. If you messed up and got the crisis event anyways, don't panic. Simply choose the broken heart option for Ian, he will still be in love in Lena but will act super jealous (using this method Ian can still be dating Cindy and Alison and it would still work). Lena must then also choose that she wants to be with Ian. BTW i you don't know what the crisis event is, it's when Jeremy tells Ian that Lena was sleeping around at the club.