"Yeah, that was hot."

"...but by the pool isn't?"

"No! Anyone could see!"

"...are you saying that it's different when it's just a risk of getting caught rather than a certainty?"

"Yeah, that." He decides to hop off the bed and spin into his clothes. "I'm annoyed now. Bye."

"Bye..."

Off he goes.

Well now he knows that he doesn't have superpowers of overriding people's consent? Yay?

No, really, genuinely it's good to know, now he has a direct concrete rejection, it's proof of concept that the world and other people aren't completely under his power or anything like that. Doyoon just is in fact a horny guy who was into Peter and he wasn't doing anything he didn't want to do, Peter wasn't personally causing him to act counter to his best judgment. 

That's pretty relieving, actually!