It's a story where John suggests they watch porn together all casual so Rodney assumes jacking off in front of each other is some normal-dude activity to which he's never been invited, and then he freaks out when he gets infatuated and can't stop staring at John's dick, thinking that he's broken some sacrosanct bro code.
And John's like, for someone with a brain the size of Jupiter, you're really not that smart, huh? Then they make out.
Thank you many times!
*edited hahaha and then I almost immediately stumbled over it, ain't life funny.