Mark and Giselle have been dating for 2 years now. Everything is going well not until Giselle's friend, Karina told her that Mark has been texting his ex, Herin for a year. Giselle knew about Mark texting his ex, but what if Karina has something more to say that made Giselle broke up with Mark?
Just when Giselle is about to left for America, Mark finally saw the girl who was always blurred in his dreams. After realizing who it is, he tried to stop Giselle from going. But Giselle's half brother, Jeno stopped him.
7 years after Giselle left to America, she came back. Their paths crossed again and realized that sparks are still there.
What happens when they had a one night stand together which creates the MISTAKE, as Mark said.
:If this feels familiar, I just want to say that this fanfic is based on a MarkSelle au I read on twitter.