I Stole the Heroine’s First Love

I entered the game world, then became FL’s best friend, even though he’s FL, how come all my fiancees were stolen from him? To the extent that because of him, I lost a lot of happiness in my life. He took all the boys and made a harem, even though he was already married! Oasuu Gasken we take revenge! By making use of his First Love, that is, the Emperor is attracted to me