I think siwon want to say " so fucking annoying those damb old women" not to jiwook..

I think it was just an illusion. Maybe Jiwook was just thinking that he was annoying for his brother

No Jiwook thought for himself that, like the person Said before; an illusion, Si won didn't acc say it

Hmm .. i think so now.. maybe he saw a smile of siwon into a bad mouth.. cuz siwon would never speak sth like that