The Girl of Steel and The Fastest Man Alive
Barry has not been in love with Iris for a long time, and it is obvious. Since she wanted him to follow his heart, Iris breaks up with Barry. In order to help get over his break up, Barry goes to his best friend: Kara Zor-El.
While there, he realizes something. Barry didn't love Iris because he was in love with Kara. After a evening as friends that makes them both realize their true feelings for one another, Barry and Kara begin a secret relationship.
But the life of a superhero is never easy, especially when you live on different universes.