The time when they actually do the deed is way later into the manhwa. According to the book, there is one more big situation, similar to the situation that happened in ep 6-19 that will happen before they actually do it. But during that situation, the sexual tension and tension itself is sure to rise. It might take some time though, but from what I've read from the book...pretty violent smut...
Hahaha, I feel like according to how fast the uploaders are going, we will likely see that scene maybe between next month to January. I could be wrong with the timing considering the upload is pretty irregular and the uploaders keep changing, but it is still very likely soon.
Also knowing how much the artist covers in one chapter is already really fast. Chapter 26-27 was an entire book chapter. Next part of the season is 'Nuclear Man' part which lasts for 5 chapters (about 10 more episodes i think?), and after that it's the big reveal and the r*. I do think that they do it for love but it will take more than several parts to get to that point because by the end of the r*, likely Taekju lost complete trust and bond with Zhenya. Hahaha sorry this must have been long to read. ( ̄∇ ̄")

i liked this manhwa, but hey i am reading too much straight sex... which is meh... makes me feel weird. i dont like it really