“Moon Lovers: Scarlet Heart Ryeo” episode 5 will see Hae Su (Lee Ji Eun), Prince Wang So (Lee Jun Ki) and Prince Wang Wook (Kang Ha Neul) becoming more entangled together.

In the preview for “Moon Lovers: Scarlet Heart Ryeo” episode 5, it looks like Lady Hae (Park Si Eun) will ask her husband Prince Wang Wook to marry her cousin Hae Su. The two cousins share a tear-filled moment together as Lady Hae asks Su to take care of Wook after she dies. Though it’s highly likely that Prince Wook’s mother and sister will oppose this, the next episode could see Su getting engaged with Wook.

However, Prince Wang So and Hae Su are also growing closer together. In the teaser, So surprises Hae Su by putting his arm around her shoulders, hinting that the normally antisocial prince has mellowed out completely around the girl. Is So already falling for her? Check out the “Moon Lovers: Scarlet Heart Ryeo” episode 5 preview below!

In “Moon Lovers” episode 4, Su not only became closer to Prince So, but also his brothers Prince Wang Eun (Byun Baekhyun) and Prince Wang Jung (Ji Soo). Eun didn’t bother hiding his infatuation for Su and had already started courting her in his own special way by giving her toys to play with. Meanwhile, Hae Su, along with Wook and So, helped out Prince Jung when he was cornered and attacked by some shady men in a bamboo forest. So and Wook ultimately drove the men away, but it’s Su who formed a new friendship with Jung, who calls her “Hae Su Nooeui,” an archaic form of “noona.”

In the previous episode, Wook seemed to be slowly developing feelings for Su. The fight in the bamboo forest where Su had put herself at risk to protect Jung seemed to be a wake-up call for the prince, who told Su, “ I thought I had lost you. I thought… I wouldn’t be able to see you again. I was scared.” They almost kissed, but their moment was interrupted before anything could really happen. Earlier in the episode, Lady Hae had asked Wook to either take a second wife or divorce her so she can die peacefully, telling him that she knows he doesn’t love her. However, it’s possible that she’s been aware all along that Wook is falling for her cousin.

“Moon Lovers: Scarlet Heart Ryeo” episode 5 airs on Tuesday, Sept. 6 at 10 p.m. KST on SBS. You can also watch full episodes of "Moon Lovers" with English subtitles here.