It was...Bad. The pacing, the characters and everything felt like author tried to bend this story to extreme.
First things first, you can't bend character sexual orientation that easily just because their faces are similar. Depending on your orientation there are specific features that you are attracted to. For example i like roundness and softness and overly fit women are a turn off, feels like touching my butt. Some character points that are more pronounced in males, if seen in a woman is a turn off. There are various degrees to that like 0 and 1. It's usually you either like softness or hardness(right or left and etc), women like fit men with pronounced muscles and hard to the touch and are likely irked off from touching something soft and round.
Next point, MC is in fact POS, dunno about the twins since their game wasn't fleshed out. But MC is indeed a POS. FMC was right to call him out on BS by playing with them both. While her actions are not good (nor her brothers), MC was trashy. If the world would be so easy that you could change your sexual preference i think we would be in a very nice place something near the heaven(or hell since more rivals means more conflict). We don't and his answer to give an answer after 1 week was utterly bad. But author somehow bended his orientation and his actions seemed just.
Normally he would clear up everything with her before giving the brother even a chance to do something. What he did? He broke off with girl while still giving the signals (basically pausing) and then starting off with the brother.
Third point, not enough chapters, we know that MC is POS but we can't judge the twins much or their reasons. For example was FMC really in love with MC or was that just brothers plans to break them apart? Was the brother a POS too? Because evidence suggests that he was. In any case many leads but not enough to have concrete judgment.
I cannot state about the trauma or state of psychotherapy in Japan but i would think after that problem arose in him, at least his mother would try to mitigate the damage or seek counsel. Somehow this massive problem was untouched by everyone until he turned 17, especially since he was going to coed school and was in his 2nd year. (Even twins didn't know, his problem would be noticed in a year max)
Also truma fleshed out very conveniently instead like the usual. Usually in these cases, men become men haters, women haters and etc. Not to the point of PTSD like feeling. Though in theory possible but it feels so artificial that you cannot overlook it.
Basically everything feels like a rubber that was stretched to every side to conveniently create this story. Remote cases are ok, but combined together it just feels like fantasy.
