I don't like where this story is heading either, but blaming Yuta for not trusting Seunghyun enough feels unfair.
It's been ten fucking years. Seunghyun left him behind for an entire decade, and now they've only been back in each other's lives for about a month. Why would Yuta suddenly believe that Seunghyun would choose him over the people he's spent his whole life protecting—Jaeil and his sisters?
Deep down, Yuta already knows who Seunghyun would choose if it ever came down to it, and it wouldn't be him. So why wait for that moment to arrive? Why not end everything now while he can still protect Seunghyun and spare himself the pain of being abandoned and not chosen all over again, just like he was ten years ago?
I hope yuta think hundred times before going to that hell hole now that seunghyun is hurt because it clearly that whatever he does seunghyun will come to save him even if it means putting himself in danger