He should've said no immediately after she asked him if he would leave Chicago should Gabby returned. For one thing he didn't leave that first time she asked him so why would he leave that second time? Secondly, he clearly forgot that he jumped out of his truck just to save her. How was that not obvious to him?
Right? I was also confused about that. He literally jumped out of the moving truck to get to her and he held back when Brett asked him about Gabby. He even told Severide that Sylvie was the only he’s been thinking about
Matt took so, long to realize he was in love with Brett. He waste so much time to be with Brett. There love was cut so short . Hope that Casey comes back to the show.