Lee Kwang-soo & Song Joong-ki
Lee Kwang-soo & Song Joong-ki. instagram.com/songjoongkionly

Lee Kwang-soo and Song Joong-ki have remained very good friends for a long time and their bromance is well-known to fans. They first met on the sets of 'Running Man.' Following the announcement that Joong-ki was marrying Song Hye-kyo on October 31, Kwang-soo has shared a hilarious photo of his friend professing his love for the tallest 'Running Man' member in the past.

As reported by various news outlets, Lee Kwang-soo posted a photo yesterday, on his official Instagram page, which showed Song Joong-ki, while he was taking a break from filming 'Descendants of the Sun.' Song Joong-ki is seen in his military costume, writing on a piece of white rock, "Joong Ki ♥ Kwang Soo (Asian prince) 2015.10.14." Kwang-soo then adds the caption to reveal his jealousy at his friend having settled down, asking, "What was all this, then?" as per Koreaboo's translation.

이건다뭐였던건데

A post shared by 이광수 (@masijacoke850714) on

In response to Lee Kwang-soo's post, perhaps, Instagram page 'songjoongkionly' posted this hysterically funnier photo depicting Kwang-soo as Song Joong-ki and Song Hye-kyo's child.

Koreaboo notes that Kwang-soo's post has since gone viral. Some fans may have not been able to take the joke and think the 'Running Man' actor is actually jealous and wasn't informed by Song Joong-ki that he was engaged. It was learned recently, through a close friend of Song Hye-kyo and Song Joong-ki, that the couple had told only a select few people who they trusted. Kwang-soo may have been such a person.

However, this seems less likely, seeing as fans have pointed out that during an awards show, Kwang-soo, who was sitting just behind the SongSong couple, tried to suppress his smile. Song Hye-kyo, sitting beside Song Joong-ki was also smiling, visibly embarrassed perhaps, by something the MC had asked or mentioned. It seems Lee Kwang-soo already knew of their relationship, maybe even their marriage plans.

@masijacoke850714 ?

A post shared by SONG JOONG KI / 송중기 (@songjoongkionly) on

Kwang-soo and Joong-ki have remained close friends beyond their 'Running Man' days. They have supported each other during fan meets by appearing as guests. Lee Kwang-soo also did a cameo in 'Descendants of the Sun.' This was when Song Joong-ki wrote the message on the white rock.

Welcome for the new baby, congratulations @masijacoke850714 ☺

A post shared by SONG JOONG KI / 송중기 (@songjoongkionly) on

 Meanwhile, it was recently revealed, that Song Hye-kyo had made a generous donation on Children's Day, to Seoul National University Hospital. The donation figure, Soompi notes, is 100 million won (about USD 86,900). A representative from the actress' agency said she had decided to donate the sum after narrating a documentary on terminally ill children, in 2016.