actually we only seen him topping but this doesn't mean he isn't versatile ! we don't know much about his preferences with someone he's deeply in love with and nothing is just black and white until it's explicitly stated that he will rather lose his dick than put it in his ass. it's common with a lot of gay folks to switch or to be vers depending on their partner, and what kind of boundaries they've established together. healthy relationships tend to go through a lot of talks, even coming to who takes the lead tonight, and if it was another story, maybe i would've ignored this possiblity since I'm usually focused on the plot only, but i believe the author is very familiarized with the queer culture and a change like this could be a major plot point to build their relationship.
i need to see yeoreum bouncing and moaning on it