It's unpopular but I agree. It's a pity bc Nanjo HAS topped Sunwha and even if it's not ultimately his preferred dynamic anymore (it's fair to have a preference don't get me wrong) it's going to feel weird for Mok's friend to have gotten to know an intimate part of Nanjo that Mok won't ever know even if he's his destined partner.
BUT the author said there won't be any switching so we should respect her decision. I just wish switching in manwhas wasn't such a rarity.

I'm sry but i want nanjo to top mokyeon I want them to be a switch couple is it only me?