Sangmin Lee revealed the behind-the-scenes story of his marriage registration. On the October 4th broadcast of JTBC variety show "Knowing Bros," couples Park Junhyung-Kim Ji-hye and Kim Ga-yeon-Lim Yo-hwan appeared as guests. During the show, Kim Ga-yeon confessed that she had tried to keep her marriage registration with Lim Yo-hwan a secret. Kim Ga-yeon said, "Among the celebrities I know, the person I trusted the most was Park Junhyung," and added, "When you register a marriage, witnesses have to sign. My husband had one of his acquaintances do it, and Junhyung did mine."

Heechul Kim mentioned that Seojang Hoon was a witness at Sangmin Lee's marriage registration. Kim Ji-hye expressed surprise, saying, "Really?" and Seojang Hoon said, "I went with Kim Junho." Soogeun Lee joked, "Both witnesses had disqualifications," indirectly referring to their divorce histories, which made everyone laugh.

Sangmin Lee recalled the time he went to register his marriage, saying, "I thought Junho Kim was the one registering his marriage, so I said, 'Congratulations, Junho,' as if I wasn't the one registering mine." He added, "Under the belief that Janghoon was protecting me, three celebrities showed up at the district office, so imagine how many people gathered. Janghoon said, 'No photos. This is a top-secret situation. Don't post this anywhere.'"

Seojang Hoon explained, "The article hadn't come out yet, so taking pictures from afar was unavoidable, but they were taking photos too close." Kang Hodong understood Seojang Hoon's consideration, saying, "Because we love the program, we were worried about spoilers."

On April 30th, Sangmin Lee registered his marriage at the Gangnam District Office in Seoul with a non-celebrity who is 10 years younger, officially becoming a couple. This marked a new beginning for Sangmin Lee. The behind-the-scenes story of the marriage registration revealed on the show attracted much interest from viewers.