I wouldn’t put it past JJK since he dgaf
Oh, so you think they didn’t know about the jinx and were just hoping he had a lasting boner, maybe even having to go the hospital? But that (him pulling out) wouldn’t have maid Junmin automatically win the match would it? They wanted him to enter but be weakened so he could lose, only then could Junmin win, like when they injured his foot

There’s one thing that wasn’t revealed: the spiked milkshake.
We know that Junmin and his thugs were behind everything, trying to bring JJK down, so they followed him around everywhere to get ahold of all his routines and see which people are the closest to him so they could hit him really hard, so ofc they must’ve figured it out that JJK and Kimmy were also getting it on BUT! HOW did they know about JJK’s jinx? That spiked milkshake was intended for JJK but Kimmy had it instead and as we could see, it made him insatiable, leaving him wanting more until he finally passed out but if JJK had drunk it, he wouldn’t have been satisfied at all and therefore he would’ve lost the match the day after. So HOW did they know that JJK had this jinx and that he had HAD to have sex before every match? We never saw this in the story but I’m guessing they must’ve found out from one of his past “lovers” and I think it was the green haired guy that got thrown out in the first chapters (who Kimmy replaced) and that Kimmy later on in the middle of the story delivered food to.