I think this was more psychological.. He knew the omega was turned on while he was holding him there.. he continued because the omega liked it. I don't believe for one minute this particular beta would do anything the omega didn't want. He's too kind, accommodating and gentle. He was in tune with the omega which showed by the last panel when the omega was more passive and kind.
You see, that’s a bit harsh. Betas can still feel empathy for omegas and alphas. It’s just different. Plus kyungsoo wouldn’t ever hurt chowon, if anything it’d be the other way around...
“You are doing it because you know I have the weakness for your tears”.
He never tried to listen. As beta he never experienced the pheromones and what he heard is omegas are physically weak, so he uses it without hesitation to get what he wants. He never let him finish why he was crying for.
Dislike it as much as you want but that shows why alphas and omegas stick to each other. And betas don’t get it.