Kit :D's Manga

Can someone please explain why he can't hear his thoughts anymore even though he fell back in love

Bitch why didn't the red hair guy just explain to him why he doesn't like/trust the sunbae??? All of this conflict going down could have easily been avoided. Obviously something bad happened in the past to trigger that reaction that the main character has blocked out of his memory from his childhood that will eventually be revealed. And it's apparently so bad the red hair guy is at the point of fucking killing himself??? Just fucking talk it out you silly little bitch