“Is there anyone in this room you’ve cheated with?” he pressed.

Mark, looking trapped, answered, “No.”

Another red light. Another “LIE DETECTED.”

My voice trembled. “Who, Mark? Who did you cheat on me with?”

He stayed silent.

That’s when I saw my sister, Melissa, squirming in her seat, her unease clear. A horrible thought hit me like a ton of bricks.

“Was it her?” I asked, my voice shaking as I pointed toward Melissa. “Did you cheat on me with my sister?”

Mark froze, his eyes shifting between Melissa and me.

“Tell me, Mark!” I demanded. “Was it her? Melissa?”

Mark lowered his gaze and whispered the one thing I feared hearing.

“Yes,” he confessed.

The machine didn’t need to confirm it, but it did. Truth.

The silence that followed felt suffocating, broken only by the sound of my uneven breathing. My mind was spinning as I looked at Mark, then at Melissa, who appeared as though she wished she could vanish into the floor beneath her.

Before I could even begin to ask another question, Uncle Sam cleared his throat.

“I wasn’t going to bring this up today,” he started, his focus fixed on Mark. “But a few weeks ago, I saw you two together. I was at the mall having lunch when I saw you, Mark, holding Melissa’s hand. At first, I thought I was imagining it, but then I saw how you leaned in close to her, how you touched her cheek.”

He paused, his face twisted in disgust. “That’s not how a future brother-in-law behaves with his fiancée’s sister. I hoped I was wrong, but deep down, I knew I wasn’t. So, when Melissa showed up today looking jittery and uneasy, I decided it was time to get the truth.”

His words hit like daggers, tearing through whatever illusion I had left. I looked at Melissa, her face covered in tears. “Why?” I managed to whisper, my voice cracking. “You’re my sister. How could you do this?”

Then, I turned to Mark. “You didn’t just betray me. You shattered everything we built together. How could you? Why?”

Mark couldn’t meet my eyes. He looked away, muttering the words that didn’t even begin to ease the hurt. “I made a mistake.”

My chest felt like it was closing in, and my eyes blurred with tears. I couldn’t forgive him. I knew that cheating wasn’t a mistake—it was a conscious decision, and one I would never be able to accept.

Without a word, I yanked the wires from the lie detector and walked out, leaving behind the man I thought I knew, the sister I once trusted, and the wedding that would never be.

Some betrayals are too deep to ever mend, and this one was a wound I couldn’t ignore.