My thoughts entirely. This reminds me of a reddit story where a woman overheard her husband calling her ugly to his friends to show off or whatever and all he had to say was "I didn't mean it" but that doesn't erase the harm if anything it makes it worse that you value people opinion of you over...
Shoehorning in that annoying ass character was NOT the only way the author could have written this, Oomori could have gotten confessed to by someone else making Yuu realize he needs to stop dragging his feet, or Itoko, knowing his "trauma" could have set up a scenario that would help him gain...
See, it's one thing if they were just a bit nicer because that's normal, but they actually sidestepped their kids and said they'd rather trade them in for their friend like it's some fantasy football team ☠️☠️☠️