Tsukissme's manga / #BL(2)

This started cute, although the plot is kinda confusing. MC is so adorable, but I actually don't like his glow-up. Why did he become like that? It's really kinda weird. The fact that their sex position will change since based on the cover, so MC is top now!?

https://toonkor367.com/%EB%A0%88%EA%B0%80%EC%8A%A4_39%ED%99%94.html