I’m Greta, 30, a marketing manager always on the go. My husband Tom and I were the perfect couple—or so I thought. One day, returning home early from a business trip, I walked into my house and heard my sister, Kelly, in the shower—with Tom. My world shattered instantly.

Instead of confronting them, I quietly left, seething. I hatched a plan. I gathered all of Tom’s belongings, dumped them at Kelly’s yard, then organized a “surprise” barbecue, inviting friends and family—including the culprits.

When they arrived, nervous and unsuspecting, I grabbed a mic and revealed their betrayal to everyone. Gasps filled the air as I threw two suitcases at their feet and told them they had 10 minutes to pack and leave my life.

Tom and Kelly, humiliated, had no choice but to go. As they left, our friends laughed and raised drinks in my honor. I walked away victorious—my world was upside down, but I had the last laugh.