You're not the only one bruh! It's like, it's not erotic enough. That's why I thought maybe he's just controlling his expression or maybe.. that's just it...
this author tends to draw faces like that!! its the same in their other works and i definitely wished the characters had more expression but thats just the authors style ig
director kang's personality is very stiff, but i agree with you on the sex scenes part.
omygad im sorry i commented on the wrong manga LMAO but i fully agree with you now.
I feel like the expression is a bit..lacking? Like the whole sex scenes and other hot stuff are awesome, but the duke's expression is a bit stiff...to me..idk. His face mostly stayed the same during sex, only with the blush added on ╥﹏╥ Anyways, just my opinion, and how I usually view art style since I usually draw more...erotic faces(￣∇￣")