well from what I understand is what the blondie was saying was that Taehwan was no better than him and that he was using Yeonwu, Yeonwu hears this and the gears pretty much start turning for the both of them. Taehwan in denial does try to suppress his negative feeling (guilt this time) how he usually does with sex... but in truth, he is no better than him and Yeonwu tells him no.

SPOILER...
EP. 35
https://m.imgur.com/a/xhDvfDT