I just realized that the author makes parallel between this chapter and chapter 4. In both chapters taeyong used nipple clams to others, and his face also gets dirty by his partners semen. But the difference is he looks annoyed when someone else's cum gets splash on his face in that chapter but here he looks happy almost deranged when it's jinwoo's cum that reaches his face.
I just realized that the author makes parallel between this chapter and chapter 4. In both chapters taeyong used nipple clams to others, and his face also gets dirty by his partners semen. But the difference is he looks annoyed when someone else's cum gets splash on his face in that chapter but here he looks happy almost deranged when it's jinwoo's cum that reaches his face.