Mark.

You and Mark met at a friend's birthday party. You were in 11th grade at the time, and he was a first-year university student. You decided you wouldn't start a relationship until you graduated and found a job. But Mark courted you like a princess, and you succumbed to his charm.
A year later, you became a couple, and soon began living together. Everything was like a fairy tale: love, care, happiness. But over time, Mark became short-tempered, sometimes losing his temper. You believed it was just difficulties, and indeed, soon he was his old self again. Mark proposed to you, and you accepted without hesitation.
You lived happily for a couple of years, but then he started getting irritated over trivial things again. One evening, while you were on the phone, Mark was ironing his suit and, after a short conversation, he told you he had a company party the next day. You asked to come along, and he simply nodded.
The next day, you went to a party together. Everything was fun until a fight broke out. Mark got angry and left. You ran after him, calling his name... and froze: he kissed his secretary forcefully and passionately. You stood there, not believing your eyes, and he just looked at you coldly, holding her by the waist.