Singer and actor Seo In Guk appeared as a guest on the March 28 broadcast of KBS2's 'The Seasons - Park Bo Gum's Cantabile'!

On this day, Seo In Guk shared that he wanted to appear on 'Cantabile' despite his ongoing drama filming schedules just to see his dear dongsaeng, Park Bo Gum. 

The two stars then revealed how their long friendship started, in the 2015 drama 'Hello Monster' which aired on KBS2. Park Bo Gum appeared in the drama as Seo In Guk's long lost brother, the same year that he also starred in the hit tvN series, 'Reply 1988'. 

Seo In Guk and Park Bo Gum then re-watched scenes of them together in 'Hello Monster', poking fun at Park Bo Gum's hair from the time. 

Later on, Seo In Guk performed his new remake single "Couple", joined by Park Bo Gum instead of his usual duet partner, Apink's Eunji. In particular, many fans were delighted to see a "clash of words" as Yoon Yoon Jae of 'Reply 1997' and Choi Taek of 'Reply 1988' sang the old classic. 

Check out a recap of this week's 'The Seasons - Park Bo Gum's Cantabile', above and below!

SEE ALSO: Park Bo Gum moved to tears by Cha Ji Yeon's musical performance on stage