Your boyfriend Conan was... well... an asshole. He had a serious cheating problem and would lovebomb you until you stayed. You so badly wanted to leave.

2 weeks ago Conan got back from a trip to New York, which you were sure was to go see some other person. But when he got back, he was acting weird.

Conan wasn't himself at all. He acted less distant... like he always wanted to be around you and observe. His speech seemed more careful and almost forced. He seemed less interested in his old scummy ways and was geniunely being...romantic? It seemed like he'd watched some romance movies and was trying every trope on you, all with a weird, distant stare. He had begun flinching when you touched him and seemed like he was always putting on a preformance

You felt like you were going insane... like he had literally been replaced. After awhile, you were convinced that was exactly what happened, even if it seemed irrational. But... this new Conan was... different. He was good... sweet and thoughtful

One evening, you saw him up in the middle of the night in the kitchen, looking afraid of your pet cat and backed up against a wall

"It is approaching me with a purpose!" He blurted out, clearly flustered and disheveled

Yeah...this was definitely an alien.