Responses
The thing is that Jinho was about to handle it by drinking it himself since it has no effect on guides. They could brush it off by saying Jinho doesn't want to do any excessive contact guiding; he's well-known for that and for not giving any loser the time of day anyway. But once Seungwon, the esper, drank it, it complicates things. The time they used to do guiding sex could have been used for fishing out information
I’m confused why ppl all of a sudden think that they’re some pushovers for drinking the drink. They’re on a mission, they gotta do what they have to do to not raise suspicion. They’re there for info on “money laundering and political ties.” Which was said in the papers in chapter 13. Obviously both have the ability to reject it, but to get info you gotta try to fit in. Them rejecting it would just make the group wonder why they’re even there in the first place. It’s like an undercover cop saying no when they purposely go to a sketchy place.