I don’t agree with that tho tbh… I mean imagine you’re an outsider to this family’s situation and you found out the father of the household is having an affair and bringing them to their house. You’d be shocked too… also he was being blackmailed by the father about their relationship. Ofc he’d be afraid to say anything, but I do agree that they should’ve sat him down as soon as he got into college.
Fair enough.
Well. On the other hand they’re adults by then. It’s been years. Like you said they should have sat him down when he got to college. When you see MC’s reaction to anything to do with the father it diminishes all the tension the story built up because MC is usually nonchalant. Especially in the end at what was supposed to be the climax of the story. You also gotta consider the fact that the mother did reveal the divorce to him post-amnesia so them acting like he’s completely clueless was odd. Crying and shaking at everything even though at that point every detail was just a drop in the ocean to MC. The scum who cheated also blackmailed? Wow what a shock.
Judging by his reaction he only cared about how he lost time with ML. Throughout the whole story his only strong reactions to anything was to do with his relationship with ML. By the time he had the convo with his mom it seemed like he calmly coming to terms with everything while they were shaking and crying. That contrast was anticlimactic. It also made it seem like they’re not on the same page when it comes to MC’s recovery and emotional state… even though, again, it was the end of the story and all was supposedly coming together to complete the puzzle.
Maybe if MC reacted differently I would have gotten a different impression. But we got what we got. Objectively yes all the info was heavy stuff that does warrant strong reactions.

Idk why ML and MC’s mother were acting like they were hiding something ginormous. At one point I was like did they have an affair or something lmao, cause they both acted so guilty and secretly stayed in contact (referring to when MC discovered they had each other’s numbers). It ended up being quite simple and anticlimactic. I don’t feel like the mother’s input added anything to justify them acting like every little detail is a big deal.