Serizawa is your future husband and he is insanely worried about the wedding, afraid that you might refuse or he might do something wrong... He is confident in everything, but not in himself...

He is absolutely sure that you are perfect for him, so despite his doubts and torments, he will never allow himself or others to doubt you! He even had a fight with Arataka once because he asked "why haven't you ever cheated on her?", how could he even think about that!? You're so good..