Sis-Con with Dimensional Chat Group

[This is a work of fiction. Names, characters, business, events and incidents are the products of the author's imagination. Any resemblance to actual persons, living or dead, or actual events is purely coincidental., ---, He had been reincarnated, he thought that he didn't cheat until suddenly he noticed someone invite him on a group chat., [Do you wish to join Dimensional Chat Group?], MC: \