Deceiver: Among us.

"I can't help but fall in love with you.." 10 astronauts were assigned as crewmates on a mission to space. A human-like creature who wasn't from earth had received a different mission from a unknown dimension which was to impersonate a crew and take down the crewmates. As he slowly do his mission, he slowly fell in love with a woman he shouldn't have, a crewmate. He couldn't help, but fall in love with her.