Responses
this is consider as a spoiler:
to clarify things, Eugene does like the seme however he was clinging to the fact that he can come back to Earth after "saving the World". Eugene finally accepted his feelings and acknowledge ML's love when he decided to stay in this world. If you read the Manhwa/novel of "Death is the only ending for the Villainess" they have the similar troupe when it comes to romantic development of their ML.
They're so unemotional lol. They look like they couldn't care less about breaking up especially the uke. Did he even really like the seme? (￣∇￣")