I've read things abt them, but havent seen much interactions btwn them. But from what little I can see, I think they share some similar interests that I think renjun may want to use as a stepping stone to be closer w/him. Honestly, to me, they seem to be friends w eo but not that close, i.e. renjun have other closer friends than jaehyun; they have a comfortable but not super close relationship. What little lore that I've read abt them being likely close when they were younger? Maybe they were then. But I think it's likely due to their relationship with winwin. If u're wondering if there's something romantic abt them, I don't see it. Not from renjun's part. Idk much abt jaehyun though.. so I can't say i know how I should perceive his interactions w renjun. If anything, I always see jaehyun as the slightly awkward, quiet person whenever he interacts with the dreamies.