On one hand, I want to complain about FMC being stupid, but it's established that her being naive is because partially due to amnesia and partially due to being so sheltered, so her actions, whilst  dumb, are justified to be operating within some internal logic, however foolish.
MC is the more interesting, as I do genuinely think he loves her, but his desire for revenge outweighs everything else, so he has to use her as a tool despite his feelings, even if it means sacrificing himself and/or the relationship if it means justice will be done.
I'm gonna bet that this is a trap and that the mom is gonna attempt to call the police, and when they met on the bridge, he's not gonna be there.