Okay, so here's the reason why:
Mike wasn't accepted by his own biological mother when he was first born. This was because she wanted a daughter instead of a son. She didn't name him at all and dropped him off at a dumpster. His biological father took him in secretly (he didn't name him either). Shortly after his mother's death, his father completely ignored him. Then a new mother figure enters his life and he was given his name. Throughout the years, Mike's father abused him. He would get beaten up and locked up in a chest, where he would spend days without food and water. One time, Mike accidentally drop a glass cup, and his father carved his own initials into Mike's back. That scar still remains. The main part is when Mike opens up about his feelings for Jay Roberts (another OC of mine) to his father. His father becomes so angry at his own son for being gay that he dragged his son into the chest, gagged and bind him with duct tape, and locked him in for a whole week without food or water. After a week in the chest, his father dragged Mike out of the chest and tried to hang him. Luckily for Mike, police officers bust into the room. His dad was arrested and Mike was released from the noose. The scars from the noose remained for a whole month, but the scar on his back still remains.