The Always War by Margaret Peterson Haddix.
I think Tessa likes Gideon because in the book he runs and Tessa follows him and they don’t know each other that well. Tessa even went into his house to see him. Then She went on a plane with him and Gideon was going to die but then Tessa knocked him to the ground and said no one is going to die.
I think Tessa is a little bit jealous because she was yelling at him when he did not take the medallion and she was saying don’t you know what it is like for the rest of us those of us aren’t heroes? Don’t you know dreary our lives are and this was going to be our golden moment for us.
Tessa likes to be with Gideon because she run after him when he does not get medallion and she goes in his house and gives him flowers.