i can definitely understand mc's reasoning. if you have very little self esteem and confidence, you'll naturally start believing that people's motives when they interact with you aren't very pure or sincere. and even after all the crazy, fun shenanigans they've been through, all it really takes to start believing that shady, pessimistic voice inside your heart is one little push. but yeah i know things are gonna be fine in the end since these two dorks are absolutely in love with each other bwahaha!