The cover is actually true tho it's the master and another guy not the one who's taking care of itsuki. The long haired guy became an uke after meeting the new guy which they still haven't shown in the manga.
In the last panel when motoki gave the key to senpai thinking that they should live together, it was obvious base on senpai's facial expression and that fake smile that he's hiding something from motoki.
I've read the korean version and honestly I love them all:< I dont hate the guy that his ex is currently dating and I also dont hate his ex.