I just finished the 24 chapters available, and have to say that I don't necessarily agree that Kou is being abusive anymore. I mean, I thought that initially, I admit. Yukio did not crossdress before he started going out with Kou and he was a hikikomori, so in a vulnerable mental state during his teenage years. Also, there is the scene where we see that Kou straight-up admits he doesn't want Yukio to wear man's clothes because he looks cuter in drag. However, there's one important aspect here that changes this dynamic and puts them on equal footing: when Yukio is faced with something he truly doesn't want to do, he WILL refuse. Such as we see is the case with the bunny costume or a one piece swimsuit. He doesn't want to do things like that and he is able to clearly refuse Kou when he bugs him about these. Also, even though Kou is straight, it's not like he pretends Yukio is a woman. He will admit he's a man willingly, he even gets turned on by Yukio using "boku" instead of "atashi". And Yukio, in turn, gets his kink on by seeing how his cross-dressing affects Kou. Plus, while you can say Yukio is influenced to cross dress by Kou, we can also clearly see that Kou is being strongly influenced by the slightest thing that Yukio does (like when he got mad because Kou did not eat the fish Yukio made).
There is a balance in the dynamic of their relationship, I think.