It seems like actor Lee Kwang Soo has been trying hard not to show any interest in other woman after admitting his relationship with actress Lee Sunbin.

On January 13 episode of SBS 'Running Man', K-pop boy group WINNER's YOON and HOONY, K-pop artist CHUNGHA, and K-pop girl group Weki Meki's Kim Do Yeon made appearance at the show.
On this day, the viewers could not help but be surprised by Lee Kwang Soo's behavior since he turned into a whole new person and showed zero interest in female guests.

Such reaction was only natural since Lee Kwang Soo previously had a reputation for being a cute ladies man until he fell in love with his girlfriend, and always welcomed all female guests with open arms.
Later on, it turns out that this episode was the first episode he shot after acknowledging his
relationship with Lee Sunbin.
Whilst solving quizzes with his teammates CHUNGHA and Ji Suk Jin, Lee Kwang Soo just concentrated on getting the right answers and never showed his cheesy smile even though CHUNGHA cutely danced in front of him the whole time to provide clues for the game.
The public had a hard time processing the fact that he truly has changed since the old Lee Kwang Soo and this guy were a completely different person.

After the episode, the viewers commented, "I've never seen him like this.", "Lee Kwang Soo must be head over hills in love with Lee Sunbin.", "I don't even know him anymore lol", and many more.

Meanwhile, Lee Kwang Soo and Lee Sunbin admitted their relationship on December 31, 2018.
 
(Kang Eunbee, Credit= SBS Running Man)

(SBS Star)