Gong Yoo and Kim Go-eun.
Actors Gong Yoo and Kim Go-eun on the set of 'Goblin.' youtube.com/tvN DRAMA

The love between a 939-year old Goblin and a high school girl, fated to be his bride in this life, is the key element of 'Goblin: The Lonely and Great God.' It is she who can finally release him from the curse of walking the earth as an undead and send his soul to heaven by pulling out his goblin sword that was thrust onto his chest. However, it now appears that Gong Yoo, who plays the titular hero of the K-drama, is also quite fond of actress Kim Go-eun, who plays Ji Eun-tak, his girlfriend.

News outlet Soompi points out a recently released behind-the-scenes clip from tvN, which shows Gong Yoo and Kim Go-eun sharing many a light moment in between their shoots and while speaking their dialogues. The actors do adlibs and laugh almost throughout the shooting. At one point Gong Yoo looks at the cameraman and asks "Isn't she pretty? She's so pretty right?" to which the 27-year old Kim Go-eun smiles, visibly embarrassed by the compliment from her co-star.

In the video, we see Gong Yoo and Kim Go-eun practising their scenes and continuously disrupting one another's work, in a light manner. We see her annoy him by taking his photo when in fact in the actual episode she was ignoring him intentionally. We also see her a little further in the clip making faces at the camera cracking Gong Yoo up, not letting him shoot his scene. But he cannot stop himself from bursting out laughing, looking at the guileless but mischievous face of Go-eun. We also see Gong Yoo offering her a bouquet of flowers with which they were filming, to Go-eun for fun.

In the scene when the Goblin has brought her to their home after saving her from falling off a building, Gong Yoo rehearses the shot where he goes and bear hugs Go-eun's character when she thinks he is angry because Eun-tak risked her life. In the behind the scenes clip we see Gong Yoo read his dialogue from his script and walk straight and hug Go-eun. But when he hugs her, a loud embarrassing noise happens, making both the actors laugh.

We are also treated to Gong Yoo waving a paper, mimicking a hand-made fan, on Go-eun's face with the latter grabbing his arm to stop him. The last segment of the video shows Gong Yoo taking a picture of Go-eun on his mobile phone. He turns to the cameraman and asks him, "Isn't she pretty? She's so pretty right?"Obviously she's pretty, with that adorable baby face of hers. In Gong Yoo's defence it can be said that he was just pointing to how fans actually see Kim Go-eun rather than expressing his own thoughts. However, if he said it genuinely, he's right anyway. Kim Go-eun is pretty.

With only three episodes left to go, 'Goblin' has become the most popular K-drama for on South Korean television. The questions that remain are what happens to Goblin and Eun tak; to the Grim Reaper and Sunny and to Park Joong-won's ghost?

A special episode of 'Goblin' will air before episode 14, which has been pushed back till January 20. Episode 13 will air on January 13, followed by the interim special. Episode 15 and 16 will air back-to-back on January 21.