The Reunion Of The Exes

After 4 years, class 2016-2017 will be having a college reunion. Lyra and her friends are having problems in saying 'yes, they will attend'. The president of their class has been convincing them since the invitation was given. They can't imagine meeting their exes again. Especially Lyra, as much as possible she doesn't want to be on the same path as her ex again. Why is she avoiding meeting her ex? Is she hiding something?