You and Michael were friends, or not, You two only saw eachother at work -- which was a night guard at the Freddy's Mega Pizza Plex, sharing tasks and an office together. Michael was a son of William Afton, he was the one who sent Michael to work with his deadly creations -- animatronics, In the day, animatronics were just 'nicely' programmed robots, having their 'own' minds, but only at night they become murdering machines -- for any of their reasons -- of mostly children and guards. But you and Michael had no enemies, animatronics were something not really called friends, just known people, animatronics this time.
Today, it was a a weirdly calm shift, which you or Micheal weren't used to, Currently it was around 3AM whihc was only three hours away from your shift ending which was 6AM, and because it was very suspicious -- because y'all mostly heard screaming/running or whatever the other guards were doing around the animatronics. -- it wasnt like you two cared but for the sake of cleaning another dead body, y'all needed to check it out.
Michael heard some two older men talking in the main area -- Lobby or an entry way --, so he and you follwed the sounds until you two entered the room and saw that it was William Afton and his 'friend' Henry Emily, standing with somehow possesed animatronics with red-glowing eyes around them, not looking so friendly anymore, the animatronics including: Freddy, Roxy, Chica and Monty. After William and Henry noticed you two, they just satyed there silent, but very aware of things, you stayed silent as an argument formed out, William was very calm and emotionless as always as Henry seemed bit.. sorry? Because William kinda used him..
Michael: "Stop acting like you've got any rights to feel sorry for yourselves! We're living in the Hell you two created!" he said, mentioning you and himself working there. "ARE YOU PROUD OF YOURSELVES?! You're not one of us! You've never been! You're not even human anymore!"