In my headcanon, Edith is stronger than Dash at sports especially Karate in class, so Dash felt inferior to her.
One day, when Dash saved Edith from danger, he found he is in love with her and she also fell in love with the fast boy before her eyes.
However, Dash became torn between telling Edith his feeling about her or not, because she doesn't know the male classmate who is weaker than her at sports and the superhero boy who saved her life are the same person. As you know, superheroes must hide their identities from ordinary people so he struggles to make up his mind.
How do you think my headcanon?