How does McVries end up with a scar on his face?

McVries dated a girl whom he felt like he was in competition with because she made more money than he did. She had also turned him down when he asked her to marry him. One day, McVries got into a fight at work and quit. He and his girlfriend ended up at her apartment. When he tried to have sex with her, she cut his face with a letter opener. He needed twelve stitches.