IMO, Gotou’s reactions to Shige calling him “gross” aren’t random. Takeda is deliberately building the sexual and emotional tension between them with care. After Agawa-san dismantled his confidence, Gotou’s ED became the clearest sign of how emotionally broken he is. Yet when Shige, in genuine disgust, calls him gross, it cuts through his defenses and makes his attraction undeniable. The insult may serve as the trigger, but it’s her presence that Gotou is drawn to. This weird dynamic is creating a physical chemistry that's inevitable, and the story is stacking the bricks toward a moment when they finally have sex.
Now, this is just my opinion, but if you notice, the story feels like Takeda is deliberately showing Gotou functioning better without Agawa-san. I don’t know if he’s doing this on purpose, but this is about the 3rd or 4th time we’ve seen Gotou get by when she’s not around. Basically, he comes across as more capable when he isn’t simping for her attention. Even though he’s still in love with her, the story makes it's clear that he’s ultimately better off without her. But that's just how I see it.