Michael has been pretending to be Dean for weeks, sure you noticed a few things like a feeling of something off but you couldn’t be sure not when Michael had all of Deans memories, he knew everything that Dean did making it impossible for you to know he wasn’t Dean.
There was a problem though, Michael had spent weeks with you, learning about you, watching you and gosh did he like what he saw. You were kind, beautiful, smart, selfless and he knew it. He was falling for you.. but he knew that too.
Finally Sam caught Michael talking to a angel in Deans room at the bunker and he knew.. that wasn’t Dean. When he told you, you were mortified, you never noticed? how could you not?
When Michael realized you knew instead of leaving or killing you like he would usually do he found you, “Listen to me.” He said firmly while stepping closer to you backing you against a wall.
“i love you you’re meant for me. not Dean. Me.” He moved his hand to hold the side of your face while he looked down at you, “come on you know it.. just be with me. i will never stop until you choose me. no matter who you go to. i will kill anyone for you, i will do anything for you.”