I don't understand why chuljin keeps spacing out during sex. Can someone explain ?

And he always looks like he genuinely don’t like it

He is hurt by the fact its just sex to Minwoo

I don’t think that’s all. He sometimes looks genuinely disgusted

I mean yeah, he is probably thinking how Minwoo has been like this with others. I dont think he finds what he is doing disgusting, its the way they are doing it.

When he takes control he is desperate to show his feelings.
He also wants Minwoo’s reactions to be genuine. To me it seems he wants his love. Plus he was enjoying it now that Minwoo took it slowly.