Yes, it's definitely miscommunication but it's also more than that. Kwon has kept his past connection to Yeon-oh a secret and also didn't make clear how personal the contents of the USB are. He has kept just as much if not more from Yeon-oh.
Kwon picked a very inexperienced and naive guy to manipulate for his own ends. There is a gargantuan power imbalance here. In age, wealth, knowledge, experience- basically every metric. And all in Kwon's favour. He says it is just a practical arrangement but then acts like he's Jeon-oh's boyfriend. If it's just a practical arrangement it's pretty callous to act like someone means something to you when you really intend to just drop them like nothing. It should also be really obvious to Kwon that Jeon-oh really likes him (everything shows on his face) and that he basically had no prior sexual experience.
People are jumping on Jeon-oh (not you op) and even saying he deserves to be raped. He's a naive and desperate person in poverty getting fuc*** around by a fairly cold-hearted and older super rich guy. I'm kind of surprised that people give Kwon such a pass. The author even described him as having predatory aspects. Just because he's not a super-sadistic psychopath like similar characters in some other manwhas doesn't make him the innocent party here.
I think it's pretty clear that Kwon likes pulling all of the strings and holding all of the cards in this relationship (rich dudes are like this irl so good depiction tbh). And as soon as something isn't in his favour he gets vicious pretty quick.
stay soft get beaten, only natural to harden up