In the preview for an upcoming episode of KBS 2TV's 'Second House 2,' a surprising revelation unfolded as MBLAQ member Thunder and former Gugudan member Mimi confirmed their romantic relationship. 

At the end of the episode aired on July 13, a preview for next week's episode was revealed, showing the two idols holding hands in Choi Soo Jong and Ha Hee Ra's second house, capturing viewers' attention.

Mimi surprised Choi Soo Jong by revealing that she has been in a relationship with Thunder for four years. She declared that they were an 'unofficial couple in the entertainment world'—a revelation that hadn't been made public until now. This revelation further piqued curiosity among fans.

During the interaction, Mimi posed an intriguing question to Choi Soo Jong and Ha Hee Ra, inquiring, "What do you do if your husband doesn't listen to you?" Thunder, on the other hand, asked, "How were you guys when secretly dating? How did you come to reveal (your relationship) to the public?"

Following the preview, both idols took to their social media to leave personal handwritten letters to their fans.

Mimi wrote, "Hello everyone, I wanted to greet you first, but the news was delivered through broadcast first. I think the fans must have been very surprised by the sudden news. So, I am writing a handwritten letter with all my heart. I have someone I want to be with for the rest of my life. He is a person who always stands by my side during the time we are together, gives me a lot of strength even in difficult times, and guides me to grow further. We would be grateful if you could warmly support our future. I hope you all are healthy and experience only the good things. -Sincerely Mimi-"

Thunder wrote, "Hello everyone, this is Thunder. I revealed my relationship with Mimi through Second House. At first, I was worried and lacked courage but I mustered up the courage for the person I want to be with for the rest of my life.  Mimi is someone who calmly cheers for me despite my lacking, warmly understands me, and firmly protects me. So, I want to take responsibility for her and live happily with her. I ask for much support. Thank you. I also want to express my gratitude to the fans who have loved me until now. I will continue to show my good side as an artist who is passionate about music."